Headii is linked to another account
Use the account that Headii was linked to.
1
Check whether you signed in with a different email, phone number, Apple account, or Google account.
2
Sign in with the original login method, then try adding Headii again.
3
If you do not recognize the account, send feedback with the message you see.
Good to know
Do not reset Headii before saving your files and checking what the reset will remove.