DC lists ProSeries now as an approved software provider:

https://otr.cfo.dc.gov/page/federal-and-state-e-file-program-modernized-e-file-business

At the top of the page it indicates "with an EIN only":

"DC participates in the Modernized e-File program for Corporation (D-20 family), Unincorporated Business Franchise (D-30 family with an EIN only) tax returns and Partnership Return of Income (D-65).
"

I'm not exactly sure what that means from a ProSeries perspective, in the 1040 module I would expect the return to be keyed on the primary SSN but maybe there's a place to enter an EIN?  I'm not on PS any more but when I was my D-30s were for rental properties so just the owners just had an SSN.

Rick