I installed with 'apt install ejabberd'
I followed the docs pointed to at the top of /etc/ejabberd/ejabberd.yml, which pointed off to old blog posts for some things (unaccepable).
I configured /etc/ejabberd/ejabberd.yml to edit hosts, acl. acme, and certificates as best I could from those old blog posts.
I copied certificates from letsencrypt into /etc/ejabberd and made them owned by ejabberd, pointed to by the yml file.
I added my host to /etc/hosts (stack overflow solution)
And yet running "systemctl start ejabberd.service" or "systemctl stop ejabberd.service" simply hangs without giving me my shell back.
That is unacceptable. Broken piece of shit.