• you need to have jumpscale installed follow this docs https://github.com/Jumpscale/bash to start installation from it on a remote machine

• please choose a machine that have at least 2 GB of RAM

• to install mattermost on a remote machine type js9

prefab = j.tools.prefab.getFromSSH("<machine_ip>", '<ssh_port>')
prefab.apps.mattermost.install('<mysql_password>') # this will creates a mysql database and add a user to it with this password 

https://docs.mattermost.com/overview/index.html

• from system console > Authentication > Itsyouonline
• set enable to True
• fill in the applicationId, secret, and itsyouonline url
• click save