This module simply responds to a presence probe sent to the server with a presence staza containing a timestamp from when the server started.
This is imagined as an alternative to the XEP-0012 “Last Activity” protocol that can seem a bit overloaded.
With the plugin installer in Prosody 0.12 you can use:
sudo prosodyctl install --server=https://modules.prosody.im/rocks/ mod_uptime_presenceFor earlier versions see the documentation for installing 3rd party modules