I use been using an app called Webcam Settings with my Logitech C930e for years and it continues to serve me well. Despite not being updated for since 2014, I haven’t run into any issues using this app in Mojave.
I use Webcam Settings to override some of the default settings, including adjusting the Zoom level and turning off autofocus. I create presets so that I can pull up settings easily.
I’ve also used this app with a variety of other cameras without issue. So, I expect it would work fine with the C920 as well.
On a side note, if anyone knows of anything similar to Webcam Settings that’s in active development…I’d appreciate you posting the name/link. While Webcam Settings gets the job done, I’m concerned that it will stop working in a future version of macOS.w