My dependents' tax IDs were expired. After e-filing the 2019 tax return, I submitted the renewals for my dependents' tax IDs by mail. During the pandemic, it took a much longer time to renew those IDs. IRS demanded me to pay extra taxes and penalties for those expired tax IDs in early 2021.
Recently I received the mails with renewed tax IDs. Can I amend the 2019 tax return and claimed back those dependent credits? Thank you for the advice.