$20 is the cost the efile a state return in the Desktop installed program, not the Online version. You can avoid the $20 by mailing your return. Go back through the FILE tab and try to pick mail for state. You might have to delete the state return and just efile federal now. Then you can add state back later.
I just saw a post about mailing state. I'm looking for it. But I found this one, read this whole thread. It might help if you want to mail state and not efile it
https://ttlc.intuit.com/community/state-taxes/discussion/state-return-pa-stuck-on-e-file-option-but-...
