As the text on-screen indicates, map each player in your class by pressing the 2-character key code on that specific transmitter for each player in your list.
NOTE: Each transmitter system is mapped differently according to which system you previously selected.
iClicker systems use AA, AB, AC...etc.
LearningWare Gameshow Pro 3, Sidekeys & Fleetwood Reply systems use: 1,1, 1,2, 1,3..etc.
HINT: If you would like to set-up names, transmitters and assign players to teams on-the-fly at game time, please see section: Teams & Players Wizard.