Problem recording with MacBook

Hi,

My equipment is as follows,

Audacity 2.3.3
MacBook pro retina 2014
Allen and Heath PX5 mixer
2 x Technics 1210

I have connected the mixer to my mac (1210’s are already connected to mixer). I have loaded Audacity and the PX5 shows up but when I press record I get nothing, if I select mic it records ok but picks ups all the noise around. I have removed and reinstalled but the same happens, I even tried the terminal suggestion to load it. I have gone into my mac privacy settings to see if the mic is allowed but it is not listed and I cant find a way to add it.

Any ideas?

Cheers
Mark

I am also running Catalina