There doesn't appear to be any way to point and click to reopen recently filed 2020 state tax return.
You'll have to wait until the IRS processes and either accepts or rejects your return before you can make any changes to your tax return.
If rejected, you can revisit your return if you need to make any edits: How do I fix a rejected return?
If accepted, you will need to amend your tax return if there are corrections you need to make: How to amend (change or correct) a return you already filed