Tnx for thisDistrokid or other type site of that sort.
You need to register a beat (as a producer) and vocal saying your channel for example, make outro with it and add it in the end of every video.
Make the site ex. distrokid to auto-claim that song and start earning immediately.
Example: Your song is claimed by Drake he gets 100% revenue right now, when your song (outro) is claimed too there are 2 claimants one of which is you and you split earnings basically.
Goodluck.