Don't have IRS pin, can't login to IRS account to get it, don't have time to receive a replacement

Filling out my son's taxes for him. I really just don't remember receiving the form with the pin for him this year.  I've done some searching, but if it came, it was misplaced. Went to the IRS website, tried to sign in, but they want a user name which I don't have in my notes. (My notes say "Unknown" for the account name.) Gave them email addresses to send us the user name, but nothing ever arrived. Tried to get id.me validated, but my son don't have a passport and, darn it, he let his driver's license is expired. (This is why I do his taxes.)

What's the best course here?  Call the number and get them to mail a new pin? The refund is less than $10.  Tempting to print the return and just mail it.