A recommended way to get Shiny Server listening on port 80 (or any below 1024)

I'm trying to set a shiny server and make it listening on port 80, but this will fail as user shiny is unprivileged. The error is the following:

Error loading config: The user 'shiny' does not have permission to listen on port 80. Please choose a port number of 1024 or above, or restart shiny-server as root. (/etc/shiny-server/shiny-server.conf:6:3)

So I was thinking on a best practice to set this port without granting to user shiny too much privileges (for security). I do not know if setting run_as would be the best way, port forwarding from 3838 via SSH or iptables rules, or which possibility is the most recommended.

My current configuration file is the following:

run_as shiny;

server {
  listen 80;
  location / {
    site_dir /srv/shiny-server/App;
    log_dir /var/log/shiny-server;
    directory_index on;

I can start this server as:

sudo -H -u root shiny-server

But not sure this is a best practice.