iOS (iPhone, iPad) is very straight forward and simple. This is because the app is publicly available on the AppStore.
Step 1: First thing you want to do is open your AppStore app and search for the app called “Smarters Player Lite”, here is the URL if you need it: https://apps.apple.com/app/smarters-player-lite/id1628995509
Make sure it's this same app here, confirm the developer name.
Step 2: Once you've installed the app you can open it and login, choose the bottom option that says “Load Your Playlist (Via XC API)”
Login using the details emailed to you after your purchase or trial. Where I have written IPTVBadger, write your username provided (eg. Badger01000) and the password below it, followed by the host.
Once you add your user it will take you to the main screen where you can download the channel list, movie list, and series list.