Android app can’t pull Wordpress data

Question

I developed an application in Java for Android, together I installed in my server in Hostinger Wordpress with the REST API. However, after running the application on my mobile, it can not download the Wordpress data. No errors in my code, and the path is correct.

package com.cunha.oapp.oapp.Tabs.TabsViews;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.text.Html;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.cunha.oapp.oapp.DetailActivity;
import com.cunha.oapp.oapp.R;
import com.cunha.oapp.oapp.RecyclerView.RecyclerViewAdapters.DesignAdapter;
import com.cunha.oapp.oapp.RecyclerView.RecyclerViewClasses.Design;
import com.cunha.oapp.oapp.RecyclerView.RecyclerViewDecorations.DividerItemDecoration;
import com.cunha.oapp.oapp.RecyclerView.RecyclerViewUtils.ItemClickSupport;
import com.cunha.oapp.oapp.Tabs.TabsUtils.SlidingTabLayout;
import com.cunha.oapp.oapp.Utils.JsonParser;
import com.cunha.oapp.oapp.Utils.ScrollManagerToolbarTabs;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

 import java.io.IOException;
 import java.util.ArrayList;

public class TabDesignPattern extends Fragment {

String urlPost;
JSONObject jsonObjectDesignPosts;
JSONArray jsonArrayDesignContent;
ArrayList<Design> designs;
SwipeRefreshLayout swipeRefreshLayout;
String[] designTitle, designExcerpt, designImage, designImageFull, designContent;
int postNumber = 99;
Boolean error = false;
RecyclerView recyclerView;
RecyclerView.Adapter recyclerViewAdapter;
View view;
SharedPreferences sharedPreferences;
Toolbar toolbar;
TypedValue typedValueToolbarHeight = new TypedValue();
SlidingTabLayout tabs;
int recyclerViewPaddingTop;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    view = inflater.inflate(R.layout.tab_design, container, false);

    // Get shared preferences
    sharedPreferences = getActivity().getSharedPreferences("VALUES", Context.MODE_PRIVATE);

    // Setup RecyclerView News
    recyclerViewDesign(view);

    // Setup swipe to refresh
    swipeToRefresh(view);

    return view;
}

private void recyclerViewDesign(View view) {

    recyclerView = (RecyclerView) view.findViewById(R.id.recyclerViewDesign);
    tabs = (SlidingTabLayout) view.findViewById(R.id.tabs);

    // Divider
    recyclerView.addItemDecoration(new DividerItemDecoration(getResources().getDrawable(android.R.drawable.divider_horizontal_bright)));

    // improve performance if you know that changes in content
    // do not change the size of the RecyclerView
    recyclerView.setHasFixedSize(true);

    // use a linear layout manager
    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity().getApplicationContext());
    recyclerView.setLayoutManager(linearLayoutManager);
    recyclerView.setItemAnimator(new DefaultItemAnimator());

    urlPost = "http://cunha.esy.es/?json=1";
    toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);

    new AsyncTaskNewsParseJson().execute(urlPost);

    ItemClickSupport itemClickSupport = ItemClickSupport.addTo(recyclerView);
    itemClickSupport.setOnItemClickListener(new ItemClickSupport.OnItemClickListener() {
        @Override
        public void onItemClick(RecyclerView parent, View view, int position, long id) {
            sharedPreferences.edit().putString("TITLE", designTitle[position]).apply();
            sharedPreferences.edit().putString("CONTENT", designContent[position]).apply();
            sharedPreferences.edit().putString("EXCERPT", designExcerpt[position]).apply();
            sharedPreferences.edit().putString("IMAGE", designImageFull[position]).apply();
            Intent intent = new Intent(getActivity(), DetailActivity.class);
            startActivity(intent);
        }
    });

}

public class AsyncTaskNewsParseJson extends AsyncTask<String, String, String> {


    @Override
    protected void onPreExecute() {
    }

    // get JSON Object
    @Override
    protected String doInBackground(String... url) {

        urlPost = url[0];
        try {
            jsonObjectDesignPosts = JsonParser.readJsonFromUrl(urlPost);
            postNumber = jsonObjectDesignPosts.getJSONArray("posts").length();
            jsonArrayDesignContent = jsonObjectDesignPosts.getJSONArray("posts");
            sharedPreferences.edit().putString("DESIGN", jsonArrayDesignContent.toString()).apply();
            designTitle = new String[postNumber];
            designExcerpt = new String[postNumber];
            designContent = new String[postNumber];
            designImage = new String[postNumber];
            designImageFull = new String[postNumber];
            for (int i = 0; i < postNumber; i++) {
                designTitle[i] = Html.fromHtml(jsonObjectDesignPosts.getJSONArray("posts").getJSONObject(i).getString("title")).toString();
                designExcerpt[i] = Html.fromHtml(jsonObjectDesignPosts.getJSONArray("posts").getJSONObject(i).getString("excerpt")).toString();
                designContent[i] = jsonObjectDesignPosts.getJSONArray("posts").getJSONObject(i).getString("content");
                designImage[i] = Html.fromHtml(jsonObjectDesignPosts.getJSONArray("posts").getJSONObject(i).getJSONObject("thumbnail_images").getJSONObject("thumbnail").getString("url")).toString();
                designImageFull[i] = Html.fromHtml(jsonObjectDesignPosts.getJSONArray("posts").getJSONObject(i).getJSONObject("thumbnail_images").getJSONObject("full").getString("url")).toString();
            }
        } catch (IOException | JSONException e) {
            e.printStackTrace();
            designTitle = new String[0];
            error = true;
        }
        return null;
    }

    // Set facebook items to the textviews and imageviews
    @Override
    protected void onPostExecute(String result) {

        designs = new ArrayList<>();

        //Data set used by the recyclerViewAdapter. This data will be displayed.
        if (designTitle.length != 0) {
            for (int i = postNumber-1; i >= 0; i--) {
                designs.add(new Design(designTitle[i], designExcerpt[i], designImage[i]));
            }
        }
        if (error) {
            Toast.makeText(getActivity(), "Houve um erro! Verifique se você está conectado na internet.", Toast.LENGTH_LONG).show();
        }
        // Create the recyclerViewAdapter
        recyclerViewAdapter = new DesignAdapter(getActivity(), designs);
        recyclerView.setAdapter(recyclerViewAdapter);

        swipeRefreshLayout = (android.support.v4.widget.SwipeRefreshLayout) view.findViewById(R.id.swipe_container);
        swipeRefreshLayout.setRefreshing(false);

        ProgressBar progressBar = (ProgressBar) view.findViewById(R.id.progressBar);
        progressBar.setVisibility(View.GONE);
    }
}
private void swipeToRefresh(View view) {
    swipeRefreshLayout = (SwipeRefreshLayout) view.findViewById(R.id.swipe_container);
    int start = recyclerViewPaddingTop - convertToPx(48), end = recyclerViewPaddingTop + convertToPx(16);
    swipeRefreshLayout.setProgressViewOffset(true, start, end);
    TypedValue typedValueColorPrimary = new TypedValue();
    TypedValue typedValueColorAccent = new TypedValue();
    getActivity().getTheme().resolveAttribute(R.attr.colorPrimary, typedValueColorPrimary, true);
    getActivity().getTheme().resolveAttribute(R.attr.colorAccent, typedValueColorAccent, true);
    final int colorPrimary = typedValueColorPrimary.data, colorAccent = typedValueColorAccent.data;
    swipeRefreshLayout.setColorSchemeColors(colorPrimary, colorAccent);

    swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
        @Override
        public void onRefresh() {
            new AsyncTaskNewsParseJson().execute(urlPost);
        }
    });
}
public int convertToPx(int dp) {
    // Get the screen's density scale
    final float scale = getResources().getDisplayMetrics().density;
        // Convert the dps to pixels, based on density scale
        return (int) (dp * scale + 0.5f);
    }

    public void toolbarHideShow() {
        toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);
        toolbar.post(new Runnable() {
            @Override
            public void run() {
                ScrollManagerToolbarTabs manager = new     ScrollManagerToolbarTabs(getActivity());
                manager.attach(recyclerView);
                manager.addView(toolbar,    ScrollManagerToolbarTabs.Direction.UP);
                manager.setInitialOffset(toolbar.getHeight());
                }
            });
        }
    }

Is there any configuration on the server that is missing?

Thank you in advance!