Toyot PZQ60-00200 Sat Nav

Hi all,can anyone help me. I have purchased a sat nav unit from a 2008 Prado as it has Bluetooth. I’ve put it in my 2006 land cruiser Sahara and it’s working great. The only issue is when I make a phone call the person on the other end cannot hear me. I can’t find a microphone on the unit. Apparently it plugs in to the back of the unit. Does anyone have one or know where I can get one?