security and privacy - microphone

In my MacBooks Security and Privacy settings for the microphone, only one app has been listed in the options available to choose from. I am confused as to why all my other applications aren't available to be selected.

I've even tried basics such as dragging the application into the area where it should e listed as an option. Quite annoying as I've done a microphone test and it works, just not on all my applications such as Steam.

please help !