Phone support is not provided with the Free Edition. If you are using a paid version of the software or if you purchased PLUS you can get phone support when customer support is there. Otherwise, post your question here and someone will try to help.
To call TurboTax customer support
Customer support is available from 5 a.m. to 9 p.m. Pacific time
What is your question? Have you filed yet? If you need to correct a person listed on your return or add one you do that under My Info.
If you haven't efiled or mailed your return or it rejected 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).