Enabling compression

I have a couple of sites on a VPS and a few still on shared hosting. When I submit my sites that are on VPS to https://testmysite.thinkwithgoogle.com/ the tool says that compression isn’t enabled. When I submit a site that’s on shared hosting, the tool says compression is enabled.

How do I go about enabling compression on the VPS?
Never mind I figured it out. http://wiki.dreamhost.com/Htaccess_tricks#GZIP