How do I correct my 2020 dependency status for the economic impact tax credit/stimulus payments with the "amend return" function? Is this even possible?

I recently realized that in 2020 I neither received the covid stimulus payment or the end of year tax break/economic impact payment. I was completely independent in 2020 so I am completely eligible - however, I CANNOT find how to edit this in the 2020 amend feature. Is this possible? What am I missing?