Ah, now I understand your question from the other thread ....
The RedbearDuo works just fine in the Particle environment. I have one myself and it works fine.
The one thing you cannot do in the Particle environment is to update the system firmware on the Duo; you have to do that through the files in the Duo github repository.
The part you are probably missing are the instructions to setup and claim the RedbearDuo to your Particle account. I found this step was tricky and the Redbear app does not match its documentation. I had to try it a few times before it worked.
The instructions are here:
The most important one is the tutorial named "Out of box experience".
The more detailed answer is that RedbearLabs used the P1 module from Particle when they developed the Duo. Recently, Particle bought the RedbearDuo from Redbear Labs.
For the latest news, take a look here:
It looks hopeful that Particle is going to provide better support for the Duo than Redbear labs was doing. I have my fingers crossed now that Particle Mesh is done and they should have more time now to look at the Duo.