I have published an article “Deploying FileMaker Server on Ubuntu Linux with Let's Encrypt SSL” In which I discuss how to set up FileMaker Server on an Ubuntu Linux server, secure it behind a firewall and use a Let's Encrypt SSL certificate with automatic safe renewals using Certbot that won’t disrupt users.
The scripts for Let’s Encrypt certificate creation and renewal are published as an open source project on Github.
The article and scripts are based on the latest Claris FileMaker Server 19.6.3 utilizing Nginx as the web server.