There seems to be some confusion as to where Microsoft Flight Simulator's “Community” folder is located, and a lot of this confusion is due to where the simulator has been installed (default or custom). Not only this, but there are also differences between the Microsoft Store install and the one purchased from Steam.
If you happened to use the default location for your installation, then you can find it here:
For the Windows Store install:
C:\Users\[Your User Name]\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\Packages\
For the Steam install:
C:\Users\[Your User Name]\AppData\Local\Packages\Microsoft.FlightDashboard_8wekyb3d8bbwe\LocalCache\Packages\
Important: Windows 10 by default hides the “AppData” folder, so you will have to go to “View” in the menu of File Explorer, and select “Hidden items” so as to see it.
For the Custom install:
If you happened to use a custom location for your Flight Simulator installation, then proceed there.
In our case it was: E:\Steam\steamapps\common\MicrosoftFlightSimulator\Community