You are required to provide your ARMA 3 Player Identification Number (PID) in your application. This is a number unique to every copy of ARMA 3. To find your Player Identification Number you will first need to launch the game just as you would normally. Once Arma 3 launches to the menu screen click on the Profile icon, as indicated in the following picture       Select your profile and click on EDIT, as shown in the following picture       Now, click