Donated troops can only be used in PvP (player vs player) battles.
Follow the directions below to utilize your donated troops:
1. Tap Play, then Find a Match to enter a PVP battle
2. Select your Squad's icon from the troop menu at the bottom of the screen
3. Select where you would like to deploy your troops
4. A "rally" flag will drop down and of your donated troops will spawn from this flag
Note: Troops will retain their level based on the Commander who donated them.