How do I get a JSON file to pick variables in Javascript?

Question

It’s a Google extension where I copy a text from a page and I copy a JSON with what was copied, but I’m not sure how to do it correctly. I managed to do this part but I’m not sure if I have a JSON.

chrome.contextMenus.onClicked.addListener(function(Clique)){
    if(Clique.menuItemId == "Clipenews_paragrafo"){
       console.log("Sucesso");
       var texto = Clique.selectionText;
       $.ajax({
         url: 'localhost',
         dataType: 'json',
         method: 'post'
          data:{ data:JSON.stringify(texto)},
     });
    console.log(texto)
}