On your remote press:
Green
Go down to Xtream Editor
Press blue to load epg
Exit Xtream Editor
Wait 5 minutes or so press epg, if nothing has populated ask your friend or whoever setup the sub to check epg as in Xtream Editor it can either be set to use their own epg or a external source url. There may be another way using epg importer or the like but I have always used Xtream Editor's own epg.