In order to redeem the key go to https://www.digitalcombatsimulator.com/en/personal/licensing/
DCS: Combined Arms gives you control of ground forces during the battle. Use the Command Map to move ground forces, set artillery fire missions, and control the ground battle. Assume the role of a Joint Terminal Attack Controller (JTAC) in multiplayer and designate targets for player-controlled close air support aircraft, or directly control armor vehicles or air defense weapons and engage the enemy.
Play DCS: Combined Arms as a real time strategy game, a first person armor warfare game, or direct the ground battle from the cockpit of a DCS aircraft like the A-10C Warthog, Ka-50 Black Shark, or P-51D Mustang.
DCS: Combined Arms supports both single player and multiplayer gameplay. When in multiplayer, different players can take on different roles such as artillery commanders, tank commanders, pilots, JTACS, etc. DCS: Combined Arms allows you full control of the battle. All roles can be changed dynamically during the battle.