I use Centos7 - and JSS is installed on it. Looking on https://www.jamf.com/jamf-nation/articles/781/supporting-apple-push-notification-service-apns-over-http-2
seems like the only change needs to be done under Settings in JSS - right?
I am not sure if I should look into Tomcat configuration and implement HTTP/2 on Tomcat as well.
I'm hosting Jamf Pro on RHEL and I followed that link to switch over. Ran successful test to make sure port was open, it was, switched the port and restarted tomcat. I did notice comms stopped a few days later and I had to kick tomcat again. Seems to be good since.