Can I get stimulus check thru 2020 tax return?

I got my 1st and 2nd stimulus check, I have some stimulus check questions for my spouse and my daughter.

1. My daughter is my dependent, but I did not get neither 1st nor 2nd stimulus check for her. Is it because she has an non-valid for work SSN? Can I get her stimulus check thru 2020 tax return?

2. My spouse does not have an SSN or ITIN yet, so we did not get his stimulus checks. He's my dependent, but he's not in the US for more than 1 year due to the pandemic. Can I claim myself as head of household, and add him later by amending my tax return? Or I have to put him into the 2020 tax return, although he cannot get an SSN or ITIN? Can he get his stimulus checks thru 2020 tax return?

It's a complicated situation. Thanks for helping.