Can’t recover my sons account

Hi guys

I made my son a Hotmail account last year for him to create his own Apple ID for his iPad. Issue is, during our move someone lost the paper that had the passwords. So I can not reset his Apple ID and Hotmail password as I can’t remember both. But account recovery won’t work as not enough information apparently, which is stupid as he literally doesn’t use his hotmail account, so what information can I give them. Anyone know how to recover his password for hotmail?