Open Me → Account → Delete account and confirm. Your account and its cloud copy of likes, notes, saved passages, reading plans and journal are deleted at once (Sign in with Apple is also revoked). Data kept only on the phone is deleted with the App.
Email support@myangbytelabs.com from the address of your Apple or Google account with the subject "Delete my account". We delete it within 30 days and reply when it is done.
If you used Sign in with Apple with "Hide My Email", you cannot send from that relay address. Email us from any address and include the relay address (on your iPhone: Settings → your name → Sign in with Apple; it ends in @privaterelay.appleid.com). We confirm the request by replying to the relay address, which Apple forwards to your own inbox.
Only a record that the account identifier was deleted (identifier and time), so that another phone still signed in cannot re-create it. A Premium subscription is not cancelled by deleting the account; cancel it in your store account.