Apache 2.4 conf to display .phps (or any file type marked with handler `application/x-httpd-php-source`) as highlighted, like with mod_php. Thanks VBart for the original nginx idea (Apache is a bit more tricky ..). There's 2 files.

01-php-fpm_source_handler.conf

### PHP-FPM Source (.phps) type handler ; conditions are taken from CentOS8 php.conf
# https://stackoverflow.com/questions/11085086/php-fpm-is-parsing-phps-instead-of-showing-code-hilighted
<IfModule !mod_php5.c>
  <IfModule !mod_php7.c>
    <Directory "/real/path/to/">
      Require all granted
      # https://httpd.apache.org/docs/2.4/en/expr.html
      <If "%{REQUEST_URI} == '/php-fpm/highlight.php'">
        Redirect 404
      </If>
    </Directory>
    ScriptAlias "/php-fpm/highlight.php" "/real/path/to/highlight.php"
    Action "application/x-httpd-php-source" "/php-fpm/highlight.php"
  </IfModule>
</IfModule>

highlight.php

<?php

try {
    if ($_SERVER['REQUEST_URI'] === $_SERVER['SCRIPT_NAME']
      || $_SERVER['REDIRECT_HANDLER'] !== 'application/x-httpd-php-source'
      || !array_key_exists('PATH_TRANSLATED', $_SERVER)) {
        throw new Exception();
    }
    highlight_file($_SERVER['PATH_TRANSLATED']);
} catch (Exception $e) {
    http_response_code(403);
}

?>