Laravel: RewriteRule in .htaccess does not work

In my Laravel app I added to the /public/.htaccess/ file a RewriteRule like this:

RewriteRule ^resources/pdf$ about

however, if I call www.mydomain.com/resources/pdf/ the I only get this error:

although my server uses APACHE and the other htaccess entries do work. Also www.mydomain.com/about does work.

Why is this not working? Here is the full htaccess file:

<IfModule mod_rewrite.c>
    <IfModule mod_negotiation.c>
        Options -MultiViews -Indexes
    </IfModule>

    RewriteEngine On

    RewriteRule ^resources/pdf$ /about

    RewriteCond %{HTTPS} off
    # First rewrite to HTTPS:
    # Don't put www. here. If it is already there it will be included, if not
    # the subsequent rule will catch it.
    RewriteRule .* https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

    # Now, rewrite any request to the wrong domain to use www.
    # [NC] is a case-insensitive match
    RewriteCond %{HTTP_HOST} !^www\. [NC]
    RewriteRule .* https://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]



    # Handle Authorization Header
    RewriteCond %{HTTP:Authorization} .
    RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]

    # Redirect Trailing Slashes If Not A Folder...
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_URI} (.+)/$
    RewriteRule ^ %1 [L,R=301]

    # Handle Front Controller...
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteRule ^ index.php [L]



</IfModule>

via Chebli Mohamed