CoAP library not working

I am working a book on IoT and I would like to include a working CoAP example using the Particle Web IDE and the Particle Argon or Photon 2.
I have tried to use the community library but was not successful. The library is here:

Has anyone gotten this to work? If not, do you know where I might find a simple CoAP client for the Argon or Photon 2. My plan is to use a Node-RED coap node for the server side.
Thanks in advance,