Migrating or moving an account is not part of ActivityPub. Mastodon extended the protocol to have a move
activity.
Unless Lemmy devs come up with something similar and extend the protocol, there is no way to properly move/migrate the account to another instance. The current solution is to create a new account on your desired instance and then export the data on your old instance and import it on your new instance and leave a note in your bio for old instance/account[^1]
Start here for details on this. According to the devs this would be nice to have but is of very low priority.
[^1]: ignoring the fact that you need to re-subscruibe to communities with manual approval and losing all your comments and posts history as well as all private messaging history and contacts.
Blaze@sopuli.xyz 2 weeks ago
Are they that common? I usually find the feature used to lock inactive communities
They are not lost, they are still there, and people know they are yours if you post your new account on your old account bio.
Lemmy shouldn’t be used for messaging, that’s why you can show your Matrix account in your profile
Dirk@lemmy.ml 2 weeks ago
Yes, they’re there, in the old account on the old instance, and not here, where the new account on the new instance is.
That is entirely not the point. (Also: messaging on Lemy and instant messaging have nothing in common and should not be confused.)