Retrieve custom tags from post

Hi All,

I would like to be able to access the custom tags for a forum message by message id. 

I have been trying to access with the meta api call, but not sure how to get the correct key to retrieve the information. 

https://lithosphere.lithium.com/t5/Developer-Documentation/bd-p/dev-doc-portal?section=commv1&leaf-id=Message.metadata#Message.metadata.key.key

My current api call is 

restadmin("/messages/id/${page.context.message.id}/metadata/key/modbar")

However, I am unsure of what needs to be on the end of modbar. Does anyone have any idea?