As long as you have not Efiled or mailed the return, you can go back in and make changes. Please see the below steps:
In TurboTax Online, sign in to your account.
Select Tax Home in the left menu.
Scroll down to Your tax returns & documents.
Select 2021, and then select Add a State (you're not actually adding a state, this just gets you back into your return so you can make changes).