How can I ever reset my son's password?

My son is non-verbal and autistic. I am his legal guardian and he has his own Apple ID. He uses an iPad to communicate. The password I have is not working, so I followed the instructions to reset it. Every time I do this, it tells me that a link to reset the password will be sent to his iCloud account. But HOW CAN I GET THAT LINK IF I CANNOT ACCESS HIS ACCOUNT BECAUSE I DO NOT HAVE HIS PASSWORD. Now, I have to wait for several days to receive a password reset link, which will go to his could account WHICH I CANNOT ACCESS BECAUSE I DO NOT HAVE THE PASSWORD.

This is truly the absolute STUPIDEST system for anything I have ever encountered.