First off I read #3, as
"your pay TV subscription"...which ESPN+ is not part of any TV subscription.
View attachment 47790
I'm with
@Boxerpups4me on this. Putting ESPN+ aside for now.....I'm assuming you also have the ESPN, ESPN2 and other ESPN family channels which may also include the SEC Network (YouTube TV does as others). To view these channels directly on the ESPN app (formely WatchESPN and ESPN3) one must sign in using your TV subscription's providers credentials. Comcast, Cox, YouTube TV...etc.
...now adding ESPN+ into the mix,
For myself, I use a ROKU connected to a big 65" TV. ESPN+ resides within the ESPN app. To view any content the first time on ESPN+ first must authenticate your account with your ESPN+ credentials you registered with. On the ROKU it gives a code to take to computer and to activate my account.
All in all, it does get confusing, but as long as everyone is happy, that's all that matters in the end.