Domain: k3v9m.32606.arklogos.us
This site is using a self-signed certificate so you will see a browser warning. This is expected.
These steps assume your DNS for k3v9m.32606.arklogos.us points to this gateway and port 80 is reachable from the internet (for the HTTP-01 challenge).
1) Install Certbot
sudo apt-get update
sudo apt-get install -y certbot python3-certbot-nginx
2) Request a certificate and let Certbot update NGINX
sudo certbot --nginx -d k3v9m.32606.arklogos.us
3) Verify renewal
sudo certbot renew --dry-run
4) Confirm NGINX is using the new cert
sudo nginx -t && sudo systemctl reload nginx
Certbot installation guide: https://certbot.eff.org/instructions?ws=nginx&os=ubuntufocal
Note: The page above is fine for Ubuntu 24.04 as well—choose Nginx + Ubuntu on the site if you want the exact dropdowns.