Du könntest ja mal beschreiben, was du bisher getan hast, um OAuth einzurichten.
Die Beschreibung zur Verwendung ist in
/t/15987/1
zu finden.
Und da steht:
Discogs API access changed to OAuth
Starting at August 15, 2014 Discogs restricts access to their API to authentication using OAuth. As a user of the Discogs Tag Source you need to have an account on the Discogs web site. If you don't have a user account yet, you can create a free account on the discogs web site via
https://www.discogs.com/users/create
When you use any of the Discogs Tag Sources from Mp3tag, Mp3tag will ask you to authorize access to your Discogs profile. You'll then have to authorize the Mp3tag application on your Discogs profile and enter the authorization code when Mp3tag is asking you to do so.