If you are muted you can press spacebar to temporarily unmute yourself. Look for it in the options.
That's poor-man implementation of this.
Push2Talk is literally "you talk when pressing button" and combined with e.g MOUSE buttons,
so it's comfortable when playing games or coding in your IDE,
you have 100% control over when talking and you don't have to have focus on the communicator(!)
If you are muted you can press spacebar to temporarily unmute yourself. Look for it in the options.