Might have been best to keep this discussion in your other thread about push notifications.
The manager app will indeed call that endpoint at startup; if the manager app is running within the Android or iOS app then the push provider will try and initialise using native code and that means getting the apps FCM token so that the manager can then target your device via the FCM API when sending push notifications.
The FCM config used in the Android/iOS app(s) has to match what is running on the manager backend hence you cannot use push notifications in the OpenRemote app from the stores with your own server as we don’t share the FCM certificates used on our demo server.
I don’t know why you would manually call this endpoint; the console should do it itself as it has the push.data.token value needed to make it all work.
Any UI app that uses the @openremote/core component will initialise the providers and provided the app is running inside the OpenRemote Android/iOS native app then the push provider should respond with the device’s FCM token which will then be passed through to the console register call.
I use this endpoint because I don’t use Console App. So, I have to send request to this endpoint manually. By the way, after trying it, I confirmed this endpoint can work by manually sending requests, and still receiving push notifications. Thanks for help!