My return is already accepted. I overlooked some Salvation Army donations. Can I add them to my 2019 return??

[CalCountry]

Unfortunately not.  Donations are only recordable for the year in which the donations are made.  However, you might consider filing an amended 2018 tax return to include the SA donation.  But that would only be useful if doing so changes your tax liability and thereby increases your refund or reduces your tax amount due.