Device registration has an expiration date. if I register a device without setting the expiration datetime value, does the device will be registered and receive notifications permanently?
or should I schedule a device registration request?
and if I should schedule a device registration, then what is the period that I should re-register the device in it(ex: each time the user open the app, after 30 days of previous registration…)?
It is recommended to re-register devices with some kind of frequency. The FCM tokens don’t expire for most scenarios. More details here. It is not clear if APNS tokens expire, my understanding Apple recommends re-registering devices upon app launch (more details here) This means you need to register the device/token with Backendless every time.
To answer your question, I believe a device/token registration without expiration will be there permanently, however, notifications will stop getting delivered when the token expires.
Regards,
Mark