unable to complete activation sign-in on Smithsonian third party app

I wrote to Smithsonian to update the link their app directs to for Directv authentication. Their response was as follows (although as I’m completing this form I see listed both Directv and Directv Stream, leading me to think they are not actually one entity as your website shows, and possibly you’ve yet to create a link for Directv Stream authentication):

Open the app, go to More > Sign In with TV Provider > DirecTV

User enters their account email, chooses "Yes, I have a password", and enters account password. If this account is unable to log in to this page on iOS, have user contact DirecTV support for assistance to combine and resync their account logins.

If DirecTV support is unable to assist you, please get a ticket number from them and ask to escalate the issue to a supervisor.