Install the dependencies: apt update && apt install sudo wget gnupg gnupg2 dphys-swapfile -y Verify the PGP Key wget -O- https://repo.3cx.com/key.pub | gpg --dearmor | sudo tee /usr/share/keyrings/3cx-archive-keyring.gpg >> /dev/null Adding stable source echo "deb [arch=amd64 by-hash=yes signed-by=/usr/share/keyrings/3cx-archive-keyring.gpg] http://repo.3cx.com/3cx bookworm main" | tee /etc/apt/sources.list.d/3cxpbx.list Add beta mirror source (can be skipped) echo "deb [arch=amd64 by-hash=yes signed-by=/usr/share/keyrings/3cx-archive-keyring.gpg] http://repo.3cx.com/3cx bookworm-testing main" | tee /etc/apt/sources.list.d/3cxpbx.list Repo Update sudo apt update -y && sudo apt-get upgrade -y --with-new-pkgs && sudo apt dist-upgrade -y && sudo apt autoremove -y Install 3CX sudo apt install 3cxpbx -y Check available version to install sudo apt-cache policy 3cxpbx Install Specific Version sudo apt-get install 3cxpbx=xx.x.xxxx Clean if there existing install sudo /usr/sbin/3CXWizard --cleanup Install SBC sudo apt install 3cxsbc -y