I have been in communication with Benjamin Pettus Customer Support Engineer at Fivetran who recommended to open a Feature request ("Being that this endpoint requires the page_access_token it would need to be accessed with the Facebook Pages connector instead of Facebook Ads. I'm waiting to hear more about this from the team, but it's likely an improvement that will need to undergo the scoping and testing process before implementation"). All the additional detail can be found here https://support.fivetran.com/hc/en-us/requests/192814

Basically what we are attempting to do is be able to retrieve all the insights and creative information that is attached to an Ad (image hash and url, video id, source url, and thumbnail, and Carousel). To be able to retrieve video source is require to do it though a page_access_token as you will do to page posts which Ben indicated to us currently is not supported in your end but will be something beneficial to add