问React / jQuery -为什么“Access-Control-Allow-Origin”标头被拒绝？

EN

import React, { Component } from 'react';
import './App.css';
import $ from 'jquery';

export default class TokenList extends Component {
constructor(props) {
    super(props);

    this.state = {
        object : []
        };
    }

    componentDidMount() {
        this.TokenList();
    }


    TokenList() {

// Method currently not working...

// Method 1
    $.ajax({
         type: 'GET',
         url: 'https://bittrex.com/api/v1.1/public/getmarketsummaries',
         contentType: 'text/plain',
         xhrFields: {
             withCredentials: false
         },

         success: function() {
            console.log('Access Granted!');
         },


// Error suggests the issue is here?
         headers: {
            'Access-Control-Allow-Origin' : 'http://localhost:3000'
         },

         error: function() {
             alert('Error making the request');
         }

     })
     }