Flow is a menu replacement system for Microsoft Flight Simulator 2020. Not only does it offer better menus, it also enables Pro users to create their own scripts within the simulator.
How does scripting work?
Scripting in Flow is fairly straightforward. Flow's scripting engine taps into the sim's javascript confines to give you access to data and functions you normally wouldn't have access to outside of JS. We've built our own internal APIs to make it easy for anyone with basic knowledge of javascript to create scripts.
Code Editor recommendations
While there is a code editor in sim, we strongly recommend using a full external code editor (like Visual Studio Code) to write your code. You can use the Working Directory function at the bottom of the Script Editor's Settings page to automatically update your code from a folder on your PC. Alternatively, you can easily copy back-forth between the Flow script editor and your external code editor.
MSFS has a tendency to reload panels at random times and might lead you to loose some unsaved changes if you create directly in the sim.