The G1000 bezel is part of Air Manager. The actual “screen” of the G1000s is from the sim itself.
It’s a rather long thread, but you may want to check out the link below - particularly the OP which describes how to install Mobiflight (required for the Garmin and many other avionics). It has all the instructions on setting it up, what you need.
The bezels for the G1000 made are originally made for X-Plane by Russ Barlow, but modified by XAxSys to work with MSFS and the Mobiflight.