How to resolve Cors error in Node

Question

I did my backend with Node/express normally and tested all routes in India and everything took place normally at the front(vuejs) made requests via Xios, all routes also worked, except the authentication route of token, someone knows why?

Error:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://localhost:3333/api/v1/authorization. (Reason: Multiple CORS header ‘Access-Control-Allow-Origin’ not allowed).

Backend app:

const express = require('express');
const cors = require('cors');

const app = express()


const authRoutes = require('./routes/auth.routes');

app.use(cors('*'));

app.use(authRoutes);

Route:

const express = require('express');
const router = express.Router();
const verifyToken = require('../middlewares/token.middlewares');

router.get('/api/v1/authorization', verifyToken, (req, res) => {
  res.status(100).json({
    sucess: true,
    message: 'Token is valid',
    decoded: req.decoded,
  });
});

module.exports = router;

Middleware:

const jwt = require('jsonwebtoken');

const verifyToken = (req, res, next) => {
  try {
    const headerAuth = req.headers.authorization;
    if (!headerAuth) {
      return res
        .status(401)
        .json({ sucess: false, message: 'No token provided' });
    }
    const [, token] = headerAuth.split(' ');
    jwt.verify(token, process.env.SECRET, (err, decoded) => {
      if (err) {
        return res.status(500).json({
          sucess: false,
          message: 'Failed to authenticate token',
        });
      }

      req.decoded = decoded;
      next();
    });
  } catch (err) {
    res.json({ sucess: false, error: err });
  }
};

module.exports = verifyToken;

In frontend I call him so:

import api from './api';
// api é um arquivo de configuração do axios, somente, e provavelmente está correto pois uso ele em outras rotas normalmente
async function authorization(token){
    const btoken = `Bearer ${token}`;
    api.get('/authorization', {
        headers: {
            Authorization: btoken
        }
    })
    .then((response) => {
        return response;
    }).catch((err) => {
        return err;
    })
}

export default authorization;

Does anyone have any idea what it might be?