As of this writing, none of our provided EA4 profiles include mod_http2. If you want HTTP2, you must customize a profile.
Since mod_http2 is not compatible with MPM Prefork, it is easiest to customize one of our profiles that uses MPM Worker, such as the All PHP Options + OpCache profile. To do this click the "Customize" button next to that profile, then under the "Apache Modules" section toggle the option for "mod_http2", then click "Review". On the next page double-check the packages that will be installed/uninstalled as a result, and click "Provision" at the bottom if you see the results you want.