How to install the WorldGuard expansion:
As this is a verified expansion you have two possible ways of installation.
In-game: You can run these commands to download and install:
/papi ecloud download WorldGuard
/papi reload
Manual: Simply click the green download button to download the expansion, then copy the expansion to the /plugins/PlaceholderAPI/expansions/
folder.
Then run the /papi reload
command.