After updating to mac os 10.15.6 audio input not working - Same with Brand new iMac

After updating my 2015 MacBook Air to Os 10.15.6 there is no line input in my sound settings. There was before and now it's gone. Is there a fix for this or an app I can get to restore being able to get audio into my MacBook Air?

This is a problem with my MacBook Air but it's also an issue with my brand new 2020 iMac. I am not able to use line input or any input for that matter on this new mac. It dense make sense. Again, is there a way to do this? or a plug in or app I should get? Or has apple gone and deleted this feature from it's OS?