I have Virtualmin installed on my CentOS7 server and few websites are currently running on this server. There's no separate Apache installation because it is using Virtualmin. However I need to install / enable HTTP/2 on my server but current resources on the internet are not helpful enough to learn how to do this since I have a Virtualmin installation on which few sites are hosted. How can I do this?
HTTP/2 support was only added with Apache 2.4.17, therefore the only way to make it work on CentOS 7 is to rebuild it manually. OpenSSL version 1.0.2 is already available with CentOS 7 though.
Perhaps the easiest way would be is to upgrade to the distro that already ships needed version of Apache.
I cannot recommend CentOS 8 due to recent events, however Ubuntu 20.04 LTS and Debian 10 are both supported with Virtualmin and have latest versions of Apache. In the future we will support any 1:1 compatible forks/clones of RHEL; recently we fixed RHEL 8 support as well and CentOS 8 Stream is also supported.