Installing this package automatically starts and runs Caddy as a systemd service named caddy. The caddy upgrade command can make this easy. You can upgrade static binaries by replacing them with newer versions and restarting Caddy. (Run echo $PATH to see the list of directories that qualify.) Place the binary in one of your $PATH (or %PATH% on Windows) directories so you can run caddy without typing the full path of the executable file. This is strongly recommended, especially for production servers.

by building from source (either with go or xcaddy).

Refer to Verifying Asset Signatures for how to verify the asset signature.from releases on GitHub (expand 'Assets').If installing onto a production system, we recommend using our official package for your distro if available below. If you need third-party plugins, build from source with xcaddy or use our download page. Our official packages come only with the standard modules. This page describes various methods for installing Caddy on your system.

Debian 11 installation guide