As a BT customer who pays for sky sports and only gets main event it is really frustrating that for or the last three or four international football matches that main event each time has chosen to show the Scotland game meaning that those of us who want to watch Northern Ireland lose out. Surely it would be better and fairer if there was an agreement to take turns for showing the various home nations teams On main event for BT customers. By the way I have nothing against Scotland and hope they progress to the Euro finals next year.
Sounds like you are on a legacy package. If you want the full range of Sky Sports channels then you will need to move to one of the newer BT TV packages which allows you to add Sky Sports if you wish.
If you want a quick fix then you can take out a Now TV day pass and watch through the app on the Youview box (not via the EPG).
The legacy main event (& sky cinema) options are bring withdrawn soon I believe too so you may want to check if a better package is available for you
I said about watching through the Youview box app but was finding the England game continually buffering and bombing so switched to casting from my tablet instead which has been perfect. Curious as the F1 race earlier was fine on the Youview box with only the occasional short glitch. I suspect bad memory management or leakage in the Now TV app on the Youview box which will be resolved overnight when the box next goes into deep sleep.