Getting "follows" after Login

This call results in a HTTP 4xx, but you don’t test the resulting HTTP Code

This URL is incomplete you didn’t specify a user_id in your query string parameters, so the API didn’t know whose follows to return

Only the Get Users API support “look up via token”

So you’d want to

You should also update your PHP code to be more error tolerant.
You don’t test if your get HTTP 200 response
You don’t test if your JSON Decode succeeded

A code example that might be of use https://github.com/BarryCarlyon/twitch_misc/blob/main/authentication/user_access_generator/php/index.php#L38