For the proximity chat to work, you guys need to instal IsleVoip, i will put here the instaler and guide you through the entire procces step by step.
After Instaling the IsleVOIP-SETUP.exe thats how it should look inside the launcer
•Step 1 : on the top right you will see "SIGN IN WITH STEAM" (needed to be able to see the server and connect to it)
•Step 2: click on server list
•Step 3: you will look for the server named [EU] TRYARCH l 3XGROWTH l AI & MORE
•Step 4: Click the server, and enjoy proximity chat along your friends
How to setup your keybinds
•Step 1: In the top right corner there should be "settings cog" like a wheel
•Step 2: Click on the gear icon.
•Step 3: Input mode should be "PUSH-TO-TALK"
•Step 4: PUSH-TO-TALK KEY (HOLD) Should be your desired button (for example as you see in the photo above)
REMEMBER TO LAUNCH ISLEVOIP AS ADMINISTRATOR FOR IT TO PROPERLY WORK WHILE IN GAME