If its not in the PS list of forms, you'll have to hit up the IRS website

Doesn't look like it's in PS.  You can check form availability here.  As Lisa says, you'll need to download it from the IRS website and file it on paper since it's not an option for online payment:

https://form-status.app.intuit.com/tax-forms-availability/formsavailability?albRedirect=true&product...