Create an RPM Package
As of December 2, 2022, there were no rpm packages for NGINX Prometheus Exporter which could be easily installed in Alma Linux 9 (or other RHEL clones). I built a package for my needs and thanks to Open Build Service (OBS) made it available to others.
Edit: Since this post was first written in 2022, I have updated it. At that time, the version of NGINX Prometheus Exporter I used was 0.11.0. At the time of update, it is 1.5.1. Also, I was building packages for Fedora 37, Fedora 38, and openSUSE 15.5. Now I am building for Fedora 43 and openSUSE 15.6.