Can I file an amended federal return without filing a amended state return for tax year 2020? I am using Turbo Tax Deluxe 2020. Amendment does not effect State taxes.

Yes.  When you get to the filing steps, you can choose to file the federal amendment only.    How to amend a 2020 return

This did not work. 

When I first filed I used Turbo tax online - free addition.

When I filed the Federal amended return, I amended return to claim myself since I could not be claimed on my parents return.  This required the Turbo Tax Deluxe to claim some credits.  This had a cost of $60.00.

The State tax for Pennsylvania is a flat 3.07% and did not affect original return.

But was added with a $50.00 fee.   I was not able to select Federal only and had to order both Federal and State and pay combined fee.  I payed for both, but a State did not apply and was no generated.   

You can fill this form out for someone to call you to discuss your unused state and possible refund.