Morning all I have tried locking channels on this box by pressing APP button which brings a box up then I enter password but nothing seems to happen ie no locked channels can anyone help thanks

Hi all and thank you for letting me join the forum I have a few Linux sat boxes and now have acquired a mag 254 box and trying things on iptv I am connected to a good portal but wanting to lock channels I have tried by press the app button then password but can't lock channels can't understand...