An IPTV player is software for opening compatible video sources. Installing it does not normally create a streaming subscription, supply account credentials or prove that any advertised channel is included. The player and the content service are separate parts of the setup.
The app is one part of the arrangement
Think of the player as a television interface. It can display a list, organise favourites and play a supported stream, but the source still has to come from somewhere. A paid player licence may unlock software features without purchasing any television package.
Find the correct sign-in method
Look at the information you actually received. A playlist address belongs in a playlist field; a server address, username and password belong in a compatible account form. A screen asking for an app activation code may be licensing the player itself rather than signing into your service.
Make the first viewing session useful
Start with one live channel, then open the programme guide and an on-demand item if your package includes it. Doing this before arranging hundreds of favourites makes installation problems easier to isolate. Keep the player name and device model with your account notes.
