One-liner for Debian / Ubuntu / Mint and derivatives:
curl -fsSL https://vpn.ninitux.com/install.sh | sudo sh
This adds the signed apt repository and runs apt install vpnrouter. After that, sudo apt upgrade keeps VPNRouter current — along with automatic passwordless VPN start via POSIX capabilities.
Prefer to add the repo manually? See /apt/ for the traditional instructions.
Other platforms: GitHub Releases (Windows ZIP, macOS DMG, Linux AppImage / tar.gz).