How to access a never created vault

Hello, my BIL bought some gen2 Reddit avatars, so the vault got created. I was instructing him how to import his vault into MM, but it just says that he needs the seed or the password to access it the Reddit vault. He could never see the seed words because the vault got created when he bought the avatars. He didn’t even create a password because the vault got created automatically. How can he find the seed phrase? He has android. On iOS I can still see my seed phrase, but I can’t find a way to find it on his phone.