Enter half on each separate return. Sounds like your 2019 joint income was too high to get the full amount. But now that you are filing Separate you might qualify for more.
When you go through the federal review tab it will ask how much you got if any. Enter a 0 in the box if you didn't get one. Or to enter your stimulus payment in TurboTax, type "stimulus" (without the quotes) in the Search box, then click the link that says "Jump to stimulus."
After you have entered your tax information and are ready for the Federal Review, it will be the first question.
If you are trying to trigger it, you can go to Other Situations, answer any questions and click Done. The next automatic selection is Federal Review and it will ask about payments received.
If you didn't get one or both of the Stimulus payments or qualify for more it will be the Recovery rebate credit on 1040 line 30. It either adds to your refund or reduced a tax due.
