Whitelist a IP using htauth (apahce 2.4) when it's behind a Elastic Load Balancer

auth.conf

            <Directory "/var/www/html/public/">
                DirectoryIndex index.php index.html index.htm
                ErrorDocument 404 index.php
                Options Indexes FollowSymLinks MultiViews
                AllowOverride All
                AuthType Basic
                AuthName "My Protected Area"
                AuthUserFile /path/to/authfile/.htpasswd
                SetEnvIF X-Forwarded-For "0.0.0.0" AllowIP #change 0.0.0.0 to your whitelisted ip
                <RequireAny>
                    Require valid-user
                    Require env AllowIP
                </RequireAny>
            </Directory>