Hi all, 

I'm building an EventItemOccurrences query for a specific event with Event Item ID 27 and among other things I need to get the linked registration URL associated with that event occurrence (if there is one). So far my query looks like - 

https://rock-sandbox.******.com/api/EventItemOccurrences?$filter=EventItemId%20eq%2027&$expand=Linkages

I am getting the expanded Linkages object with a valid RegistrationInstanceID, but the UrlSlug field is just an empty string, and I know for a fact I have a registration URL associated with this Registration. How can I access that URL to add it as the href for a link?