1st stimulus check

I never received my 1st stimulus check. IRS sent my 2019 tax refund to my bank account. So they had my bank account info. I received the 2d stimulus check at the same bank account I received my 2019 tax refund. According to IRS I can claim that 1st stimulus check as a tax credit on my 2020 tax return. Where is that  exactly on any tax form as I can not find it?