How can I fix an error? I put wrong amount for stimulus payment

You can re-visit that screen.

TO GET TO THE STIMULUS SECTION OF TURBOTAX:

Go into your account and click "Tax Home"

On that screen click "Other Tax Situations"

When the drop-down opens, click "Let's Get Started" or "Review/Edit" to move forward 

There may be a delay when opening to this next screen

Scroll to the bottom of this screen and click "Let's keep going" 

The next screen should read "Let's make sure you got the right stimulus amount" (If not, click continue to move forward)

Scroll down and click "Continue"

The next screens will ask if you received the stimulus, which ones and how much. 

The software will calculate a credit if applicable.