In forum found some posts from 2012 regarding this and I cheked the FileHosting tab in download station settings and youtube.com is missing. How to enable this? Try this fix https://community.synology.com/enu/forum/1/post/159054. It's working for me.
This video includes topics: 1. setup guide for "Synology Download Station" 2. advised setting for batch downloading 3. setup guide and using tips for mobile APP DS Get 4. smart method to...