How to Initiate context class for DTL

Hi, I think it's a simple question this at the end of something fairly complex

I've a DTL to go to a target class in context 

I get the error CLASS DOES NOT callrequest=##class(context.ConnectDocumentRequest).%New()'

I attempted to add code to initate the context with 

set context.ConnectDocumentRequest =##class(Penn.EDT.Messages.ConnectDocumentRequest).%New()

I know there is something basic i am missing but have not seen covered in any tutorials i have done. 

I see an example using Assign I tried assigning my context as 

$CLASSMETHOD("Penn.EDT.Messages.ConnectDocumentRequest","%New")

What is it i am missing before the DTL (yes i accidentally named it .BP instead of .DTL)