I am getting the title error after running the following function in React:

  const postToApi = (event) => {
    event.preventDefault();
    axios.post(process.env.API_POST_URL, {step : "3"}) 
      // API_POST_URL: http://localhost:4000/api/donate
      .then(res => {
        console.log(res);
        console.log(res.data);
      })
  };

My React app is on localhost:3000. Mentioning this because the file causing the error is: isURLSameOrigin.js:51

I am getting the title error after running the following function in React:

  const postToApi = (event) => {
    event.preventDefault();
    axios.post(process.env.API_POST_URL, {step : "3"}) 
      // API_POST_URL: http://localhost:4000/api/donate
      .then(res => {
        console.log(res);
        console.log(res.data);
      })
  };

My React app is on localhost:3000. Mentioning this because the file causing the error is: isURLSameOrigin.js:51

• javascript
• axios

• 1 Don't forget to proxy your requests to the server during development. You can achieve this by adding "proxy": "http://localhost:4000" property to your package.json file. – alegria Commented Dec 1, 2018 at 21:11
• Thank you, I have done this and reloaded the page. I get the following error: Access to XMLHttpRequest at 'http://localhost:4000/api/donate' from origin 'http://localhost:3000' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. – Sean D Commented Dec 1, 2018 at 21:20
• Now you have one step closer to the solution. Cross-origin requests are by default blocked in most of the servers. You need to enable cors on your server side. Which app-server/web-server/container do you use for this backend? – alegria Commented Dec 1, 2018 at 21:34
• I'm using Express.js, I will look into enabling CORS now, thanks again. – Sean D Commented Dec 1, 2018 at 21:40
• You're wele, glad to help. – alegria Commented Dec 1, 2018 at 21:41

1 Answer 1

Have you recently added the URL to your .env? If so, try stopping your npm/yarn and start it again. Applications pile your .env at the beginning of your dev server. If that does not work have you tried placing the URL directly into it?