I'm following this tutorial here, and the step at https://www.youtube.com/watch?v=sgscChKfGyg&list=PLO6KswO64zVvcRyk0G0MAzh5oKMLb6rTW&index=1 doesn't work for me. Specifically, it's the step where we have a "code" read:all access and we exchange it for an an access token and a refresh token by sending a request of the form

https://www.strava.com/oauth/token?client_id=ID&client_secret=SECRET&code=CODE&grant_type=authorization_code

when I do this with my value of ID, SECRET, and CODE I get a page that just says "{"message":"error"}" or I get the 404 page with the red traffic light (I've tried it several times with a few variations on the scope I'm requesting).