All OAuth tokens invalid?

API
10
  1. that is step one, redirect the user to twitch
  2. they are returned to you with a ?code
  3. and that code needs to be exchanged for an access token.

It sounds like you are not doing step 3:

3) On your server, get an access token by making this request:

POST https://id.twitch.tv/oauth2/token
    ?client_id=<your client ID>
    &client_secret=<your client secret>
    &code=<authorization code received above>
    &grant_type=authorization_code
    &redirect_uri=<your registered redirect URI>
1 Like