@relink Cloudron does not work without a domain name. Many features like DNS integration, certificate management, reverse proxy setup etc all require a domain name.
Maybe you can try a setup like this:Pick an imaginary domain name like relink.home Choose the noop (only for development) DNS provider. In Advanced section, choose Self signed certificates
In your router/DNS, just add entries for *.relink.home and relink.home to the server's IP. Alternately, add those entires to the /etc/hosts of your PC. You should then be able to reach, my.relink.home and install apps.