sudo apt-get update
sudo apt-get -y upgrade

sudo reboot

wget -O- http://downloads-global.3cx.com/downloads/3cxpbx/public.key | sudo apt-key add -

# Add repository to Debian 9
echo "deb http://downloads-global.3cx.com/downloads/debian stretch main" | sudo tee /etc/apt/sources.list.d/3cxpbx.list


sudo apt update
sudo apt install -y net-tools dphys-swapfile
sudo apt -y install 3cxpbx

....................................
_____ _______ __
|__ // ____/ |/ /
/_ ___/ / /___ / | 
/____/\____//_/|_| 

Welcome to the 3CX Configuration Tool
Help https://www.3cx.com/docs/manual/

Press ESC to go back.


Select how to run the tool:
(1) Using a Web Browser
(2) From Command Line
Enter option: 1