Unfortunately there is no way to turn your mic off in pro clubs unless there is a button on your headset.
However, one way you can get around this because obviously you still want to have some game sound, is to setup an Xbox or PlayStation party. This will change your microphone from speaking in game to speaking in a party.
And if you don’t want anyone to join you can just set the Xbox or PlayStation party to invite only.
We’ve looked all over and found that this was the only way to not speak in game in pro clubs.
Some headphones have detachable microphones that just plug in. If this is the case just unplug the microphone. But only do this if I you know it is detachable because you don’t want to be breaking your headset. But like we mentioned the alternative way is to just setup a party and set the party to invite only so no body can join whilst you are mid game.