Ubuntu Server Installing PHP 7 WITHOUT Apache
If you just request php7.0, it'll install Apache as default. Do apt-get install php7.0-fpm and it'll install as FPM instead, leaving something like nginx up to you.
Use the command:
sudo apt install php7.2 php7.2-common php7.2-cli php7.2-fpm
It will require the php7.2 dependencies in strict mode (WITHOUT apache2).