How can you remove the namespace from the XML Request Message?

Is there a configuration that would remove the namespace from the XML Request Message?

It needs to look like the following:

I also need to know how to add the above encoding.   This came from an XML Request Message from a REST Web Service Operation (POST Method) that uses a Document Type Message.  When I selected the ‘No Namespace’; then
saved the message, the error message, ‘Cannot save message when document doesn't have a defined namespace. (244,247)’ was displayed.