keeps getting invalid_request Invalid redirect_uri.

Hi,

If the initial authorization began on a native application, use your App ID (e.g., com.mybrainsolutions.mybrainsolutions) for the value of client_id. Otherwise, if the authorization began on the web application or non-Apple platform application, you should use your Services ID (e.g., com.totalbrain.app) as the value of client_id instead.

Additionally, you'll want to make sure your Return URLs are identical to the redirect_uri provided in your authorization and/or validation requests.

Please let me know if the information about does not resolve your issue(s).