1) making sure your web server user (something like `http`, `apache`, `www-data`, `nginx`) is part of the `matrix` group. You should run something like this: `usermod -a -G matrix nginx`
2) editing your configuration file (`inventory/matrix.<your-domain>/vars.yml`):
**Note**: even if you do this, in order [to install](installing.md), this playbook still expects port 80 to be available. **Please manually stop your other webserver while installing**. You can start it back again afterwards.
**If your own webserver is nginx**, you can most likely directly use the config files installed by this playbook at: `/matrix/nginx-proxy/conf.d`. Just include them in your `nginx.conf` like this: `include /matrix/nginx-proxy/conf.d/*.conf;`
**If your own webserver is not nginx**, you can still take a look at the sample files in `/matrix/nginx-proxy/conf.d`, and:
- ensure you set up (separate) vhosts that proxy for both Riot (`localhost:8765`) and Matrix Synapse (`localhost:8008`)
- ensure that the `/.well-known/acme-challenge` location for each "port=80 vhost" gets proxied to `http://localhost:2402` (controlled by `matrix_ssl_certbot_standalone_http_port`) for automated SSL renewal to work