Debian 9 PHP version too old for Nextcloud 16

Please note currently Debian 10.2 Buster is out. Certainly, Debian 10 Buster provides everything out of the box to meet the Nextcloud server installation requirements .
:shield:

IMHO the goal should be a PHP 7.3 install. Please choose libapache2-mod-php7.3 over php-fpm as a home user certainly.
:safety_vest:


Why Apache2 with libapache2-mod-php7.3 but not NGINX and not php-fpm as a home user?

The NextCloudPi rationale could be worth a reading, although only deducted from Debian and not a standard system, I presume. Some background info and discussion were provided by the two posts of the same thread as was:

Hope this helps.
:nerd_face:


Happy hacking.
:sunflower: