The "!rename" command, which was previously used to transfer loyalty points when changing usernames, has been permanently removed in favor of a new system.
If you've changed your Twitch username, your points will be automatically transferred to the new username the moment you first type in chat after the username change. If for some reason this is not the case and your points are still not transferred, you'll have to get your points transferred by the streamer or someone from their mods team.
If you're a streamer or moderator, you can follow the steps from this article to learn how to move points between two accounts. We apologize for any inconvenience caused and appreciate your patience as we work on upgrading the loyalty points system to allow for automated points transfer after renaming accounts.