The path is mentioned in the document, but here it is.
In case of Microsoft Store version, the configuration of the throttle can be found here: %LOCALAPPDATA%\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalState\packages\<name of a32nx folder in community folder>\work\ThrottleConfiguration.ini
In case of Steam version, the configuration of the throttle can be found here: %APPDATA%\Roaming\Microsoft Flight Simulator\Packages\<name of a32nx folder in community folder>\work\ThrottleConfiguration.ini
You need to start the sim with the mod installed first, then exit the sim.
The files aren’t there untill you do that.