Hi Linlin,
Documentation for content filtering Youtube can be found here:
https://documentation.meraki.com/MX-Z/Content_Filtering_and_Threat_Protection/Content_Filtering
Here's more from the above page:
Youtube for Schools: Enables Youtube's 'Youtube for Schools' functionality. This also requires you to enter a Youtube EDU ID. Details on Youtube for Schools can be found at http://support.google.com/youtube/bin/answer.py?hl=en&answer=2592715.
Essentially, from your Meraki Dashboard you navigate to Security Appliance > Configure Menu - Content Filtering > Search Filtering - Enable Youtube for Schools > Enter your EDU ID.
You will need the MX Advanced Security License to access the MX content filtering features.
Have a great day!
