The problem of LAMP showing PHP files on the clear, upon new installations, or when migrating Apache configurations is fairly known.
Apache often does not know the mime type of the php file(s)/script(s), and thinks they are pure text files, and handles them as such.
Apache has them to be told the mime type of the intended extension name is
As for activating it, you might have the mime module for Apache; the configuration file usually is
/etc/httpd/conf.modules.d/mime.conf. (have not checked it out yet)
Lacking that file/module, I would prefer to add it to
I would prefer not to touch
15-php.conf as it might get updated with new versions of PHP.
So to get Apache to recognize .php files as scripts, it needs to be added:
AddType application/x-httpd-php php