How do I amend my tax return due to the American Rescue Plan?

I received an email stating that now that my AGI is lower I am eligible for additional deductions and credits. And the next step says to amend my federal tax return and not the state return. I am not sure what I am supposed to amend and I do not want to mess my return up on my first amendment. Please forgive me if this is so obviously easy and I'm missing the point