You don't need to enter it as interest, enter it as other income
Type other reportable income into the Search Box and click the “Jump to other reportable income” link
-OR-
Click Federal on the left side-bar
Click Wages & Income along the top
Scroll down to the last section Less Common Income and click Show more to open drop-down
Scroll down to last section Miscellaneous Income and click Start
Scroll down to the last section Other reportable income and click Start
Enter the description as "To file for Recovery Credit" then enter 1 for the amount
That should do it.
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 until you do get to that screen)
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.
For the stimulus reporting: