Using the following wsdl:

According to an example we need to set the namespace in the soap:envelope. How to do this in Dataflex?
Sending it without "xmlns:twinfield=""" results in an error: "Server was unable to process request. ---> Value cannot be null.Parameter name: key"

Working from Postman:

<soap:Envelope xmlns:soap="" xmlns:twinfield="">    
Any thoughts how to set the psnamespace?