All correct.

Once your app has received its token from GCM or APNs it must send it to the Joomla. In this way jBackend can register the app+device and can send push to it. To do this call the above URL with effective values into params and you will find your device registered on Joomla backend.

The second step is to schedule and execute a push notification. I am assuming you have already created a jBackend app entry and configured for pushes. If so, just create a new push, it will be scheduled after you save it. To start the sending process just call the scheduler URL.

Maybe this guide and video can hep you:

www.selfget.com/newsblog/55-a-push-notifications-platfom-for-mobile-apps-with-jbackend.html

Kind regards,
Luigi

Hi and sorry for delay.
You can get the big picture about jBackend reading documentation available here:

www.selfget.com/documentation/jbackend-joomla30.html

I can offer any kind of support as freelance, as described here:

www.selfget.com/services/technical-support/jbackend-custom-modules.html

Let me know if you need more info.

Kind regards,
Luigi