I apologise, as I know this problem has been raised before, but the published "solution" in Community does not work. I bought a Windows 11 laptop a few months ago, and it will not allow me to install the Now TV Player via the process outlined in Now Tv, as it is not a Microsoft verified app. One of the solutions suggested on the internet is to move out of S mode in Windows 11, but this is an irreversible step which Microsfot caution against, and it does not guarantee the app being installed anyway.
What do other Windows 11 users do?
They have your experience with Now, and/or with countless other apps they would like to run, and they eventually get so frustrated with being locked in the playpen that they exit S mode, with due safeguards like good AV, just as they cast off training wheels on their first bicycle as a child, exchanging a little stability for a lot more freedom.