Can't get .php file using Axios in my react app

I’m creating app using create-react-app. I created small component just to test if I can get some json data from php file. I’m getting it using axios.get() but unfortunately browser can’t find it. I’m constantly receiving an error 404 (Not Found). Where am I making a mistake?

EDIT:

My component:

import React,{ Component } from 'react';
import axios from 'axios';


class AxiosTest extends Component {
  constructor(props) {
    super(props);
    this.state = {
    }
  }
  handleRequest = ()=>{
    axios.get('./index.php').then((response) => console.log(response));
  }



  render() {
    return (
      <div className="container">
        <h2 className="">testing axios</h2>
        <button onClick={this.handleRequest}>Click to log data to 
console</button>
      </div>

    );
  }
}

export default AxiosTest

Index.php and AxiosTest.js are in the same folder

Please give more informations about your code. There could be a lot of mistakes…