Paramount plus with showtime

I’m being billed and I can watch through my cable box but I don’t have a login to watch through the app or on my phone. Comcast isn’t listed as a provider to activate from the list in the paramount t app and paramount isn’t listed on Xfinity.com/yoursubscriptions 

I can watch through my cable box, no problems. I need the ability to actually login to my paramount account and that I currently cannot get. Please help