reactjs - React - axios - blocked by CORS policy. How to unblock

I am running a simple API request to return data to a simple API search I've written. I say it's simple API call because there is no authentication needed and I can do it in python very simply.

However, I am having issues when using Axios in React.

Code:

 axios.get('https://www.keyforgegame.com/api/decks/59554ab7-b414-4220-8514-408a0dbf572d')

I've tried looking here and everyone one makes it sound so simple, but I can't seem to do anything. I've tried.

axios.get('https://www.keyforgegame.com/api/decks/59554ab7-b414-4220-8514-408a0dbf572d', { crossDomain: true })

and

axios.get('https://www.keyforgegame.com/api/decks/59554ab7-b414-4220-8514-408a0dbf572d, {
        headers: {

          'Access-Control-Allow-Origin': true,
        },
        })

But I keep getting errors like
Access to XMLHttpRequest at 'https://www.keyforgegame.com/api/decks/59554ab7-b414-4220-8514-408a0dbf572d' from origin 'http://localhost:3000' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

or

Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Do I need to put something in the header to make this work? Or is this some kind of setting I need to make in react.

Help!