- On Debian-based distros: `sudo apt install apache2`
- On Fedora-based distros: `sudo yum install httpd`
2. Install [Let's Encrypt](https://letsencrypt.org) to get a free TLS certificate. The easiest way to install is to use Snap: `sudo snap install certbot`.
3. Run `certbot` to get a Let's Encrypt certificate: `sudo certbot`. Follow the instructions given to validate your domain name and install the certificate only. You may choose to redirect HTTP traffic to HTTPS instead (which attempts to secure every connection even when the client device does not request it). Let's Encrypt does not issue certificates for IP addresses. if you don't have a domain name, but you can use a service like NoIP.
4. Locate the Let's Encrypt Apache2 configuration file. It's usually in `/etc/apache2/sites-enabled` and called "000-default-le-ssl.conf" or similar.
5. Add the following lines to the Apache2 configuration file between the VIrtualHost 443 tags. This will redirect Apache's document root on your webserver to instead point to RTL. Change "/" to something like "/rtl" if you would instead like to redirect "/rtl" to RTL and do something else at the document root. Change "3002" to whatever port number you are using if it is not 3002.
This disables normal HTTP access to your server except if the client is on the same machine as the server. This will allow you to access http://localhost:3002 (or whatever port number you are using) on a browser that is on the same machine as RTL, but otherwise, you will have to access RTL through the Apache2 reverse proxy at https://yourdomain.tld/rtl, which will secure the connection with HTTPS.
Note: Occasionally you will receive "Invalid CSRF token, form tempered" when attempting to log in to RTL. If that happens, refresh the page and try again.