You can install Virtualmin in Raspberry Pi with just a simple modification on to the install script.
I have my Raspberry Pi 4 installed with Pi OS Bookworm and it is based on Debian Linux 12 using the install script.
What you need to do is
1. wget http://software.virtualmin.com/gpl/scripts/install.sh
2. sudo nano install.sh
3. Find the text “get_distro”
4. Add in os_type=”debian” after get_distro
get_distro
os_type=”debian”
log_debug “Operating system name: $os_real”
log_debug “Operating system version: $os_version”
log_debug “Operating system type: $os_type”
log_debug “Operating system major: $os_major_version”
What this does is, it will force the script to recognize the host as a debian operating type.
Execute the script … It should install without any issues.
Reference