Normally a long press on a channel which is not in favourites will add to favourites.
Check the list of favorites, maybe channels have been added and you don't know
As I see you are newbie here
If you have valid rapid iptv subscription contact your seller
If you don't have rapid iptv service then contact your provider
As @Hectorious explained you need to check all this details
;) :D
Otherwise the famous solution after "Authorization Failed on above host" error is checking url host name and change it to
http://smarters.link
:)