You should ALWAYS review the return carefully BEFORE filing the return and that option is part of the FILE tab process or in the Print Center ...
How do I preview my TurboTax Online return before filing?
You can view your entire return or just your 1040 form before you e-file:
- Open or continue your return.
- Select Tax Tools in the left menu (if you don't see this, select the menu icon in the upper-left corner).
- With the Tax Tools menu open, you can then:
- Preview your entire return: Select Print Center and then Print, Save, or Preview This Year's Return (you may be asked to register or pay first).
- View only your 1040 form: Select Tools. Next, select View Tax Summary in the pop-up, then Preview my 1040 in the left menu.
If you haven't efiled or mailed your return you can go back in and change anything you want. Do not click on Amend! Click on Add a State to let you back into your return.
From Tax Home (the first screen you see after you sign in), scroll down to Your tax returns & documents. You may have to select Show to open the drop down.
Select 2020, and then select Add a State (you're not actually adding a state, this is just the workaround).
Maybe you should consider using the Desktop program. Then you can see all the forms and enter directly into them. And the Desktop program has more features and other advantages over the Online version.