Son filed with wrong status depende

Hello

 

I see similar questions asked and answered (at least the first part anyway).  I'm going to use TT to correct my son's return for 2019.  He mistakenly filed as a dependent (he is not).  Consequently he was excluded from the first stimulus payment in 2020.

 

I know he'll have to file an amended return (assuming by mail, but maybe not).  Is there any way for him to claim that first stimulus payment?  Or can he try to recoup on his 2020 return when he files.  Furthermore, will he still be able to get second payment that is currently being paid out in Jan 2021?