This module implements support for a Tigase XMPP extension, Priority of notifications. It is a custom extension to XEP-0357: Push Notifications.
It is planned that this will evolve to a XEP in the near future.
Add to modules_enabled, there are no configuration options.
Not tested, but hopefully works on 0.11.x and later.
With the plugin installer in Prosody 0.12 you can use:
sudo prosodyctl install --server=https://modules.prosody.im/rocks/ mod_cloud_notify_priority_tag
For earlier versions see the documentation for installing 3rd party modules