Behringer Air x18 to connect to Audacity but no signal

Hello

I am using behringer Air x18 digital usb mixer to connect to audacity

I can hear my voice through headphones but I cannot record it as the signal isn’t coming just a straight line. I have selected my mic as in 1-2 behringer x air and out as behringer x air on audacity pls help to set up thanks

The lack of response to your post is probably because none of the regular forum contributors have a Behringer x18.

Where is that selected?
Which physical inputs are you using in the x18?