1. Navigate to the following folder

    cd /opt/bitnami/apache2/conf
  2. Edit httpd.conf via your file browser or via nano

    nano /opt/bitnami/apache2/conf/httpd.conf
  3. If you want to allow a specific URL then add the following

    Note, you must do this on the parent site (the site that's hosting the content you wish to embed)

    <IfModule headers_module>
    <IfVersion >= 2.4.7 >
    Header always setifempty X-Frame-Options "ALLOW-FROM https://www.stumbleupon.com/"
    </IfVersion>
    <IfVersion < 2.4.7 >
    Header always merge X-Frame-Options "ALLOW-FROM https://www.stumbleupon.com/"
    </IfVersion>
    RequestHeader unset Proxy
    </IfModule>
  4. If you want to allow all URLs (Pink Panda site enables this)

    <IfModule headers_module>
    <IfVersion >= 2.4.7 >
    #Header always setifempty X-Frame-Options SAMEORIGIN
    </IfVersion>
    <IfVersion < 2.4.7 >
    #Header always merge X-Frame-Options SAMEORIGIN
    </IfVersion>
    RequestHeader unset Proxy
    </IfModule>