Delete your account
Deleting your Jackdaw account is permanent. It removes your devices, sign-in keys and passkeys, friends, blocks, ratings, lesson progress and push tokens, and clears your player name. Games you played stay for the other players, with your seat shown as "Former player". (Details)
Easiest: in the app
Open Jackdaw → Settings → Delete account.
Without the app
Prove the account is yours with its account key or a passkey you added to it. If you never backed up your account, it exists only on your phone: delete it in the app.