this website has one of the ones youve already tried https://www.atxcommunity.com/topic/14415-please-provide-your-states-ein-and-address-that-would-be-sh...

but I think you may just be having a software issue, is it telling you the numbers dont match?  The TIN needs to be entered at the very top of the 1099G worksheet, as well as the very bottom of it.

FWIW if this is a state refund that isnt taxable because they didnt itemize last year, you can go to the Carryover worksheet and delete the refund amount.