GarryFxV1.01 bugfix (Download this if you have downloaded GarryRealV1.25)

You can access Garryfx in the Spice section of the Pure PP in-game app.

You need to download this manually to the Assetto root folder, meaning the extension folder inside the GarryFxV1.01.zip needs to be dragged and dropped into the Assetto root directory:C:\Program Files (x86)\Steam\steamapps\common\assettocorsa.