You must have Paramount Network through a participating cable TV provider to unlock Live TV and more full episodes. Paramount+ account logins cannot unlock Paramount Network's app or website.
To see the list of participating TV providers, choose "Unlock All Content" or "TV Provider" in the app's settings. On the website, try to log in to Live TV or a locked episode and click "Choose Your TV Provider". Select "View All Providers" to search for a provider whose logo is not displayed.