Hi again. This error indicates that there's no backup data associated with that particular MSA account. Does you still have the old device where you did the backup from? If so, they you check under app settings which MSA account is associated with your backup. If not, then there's no way to tell them which account was used. We can only suggest you try with every MSA account that you own. This is supposing that your accounts were successfully backed up in the first place.
Please let me know if you need more help. If the answer was helpful to you, please accept it and, optionally, provide feedback so that other members in the community can benefit from it.
Okay. Thanks so much! :)