Need help with my ps 4 account without password

we had an relative who gave us this account, gave us a password, a nickname, etc. and the phone on which the account information was broken and lost, of course it sounds strange, but we need a password for this account, but the only thing I remember is some games, the account itself is on my ps 4 what to do with it ( I understand what do you want to say that you just need to tell a friend, but my brother and I don't remember who it is at all, but it's our relative, just how can we return it to the account) just please tell what I can do with account