Deploy TURN Server for Mattermost

I need a self-hosted TURN server deployed for the Mattermost calls plugin on an Ubuntu Linux server.

Requirements:
- Install and configure TURN server (e.g., coturn)
- Ensure it's secure and accessible
- Integrate with Mattermost calls plugin
- Provide documentation for maintenance

Ideal Skills:
- Experience with TURN servers
- Proficiency in Linux, especially Ubuntu
- Familiarity with Mattermost
- Strong security practices
- Good documentation skills

SSH access will be provided.