Installation:
Unzip causewayfiller.bgl to PanamaFS-X to a temporary folders, copy its content at C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\Addon Scenery\PanamaFS-X\scenery or
C:\Program Files\Microsoft Games\Microsoft Flight Simulator X\Addon Scenery\PanamaFS-X\scenery
Go to MSFS and enable the scenery via Settings/Scenery Library/Add Area.