Does the registration token refresh whenever the app is launched in iOS?

Question

When I install app for the first time and it asks for the permission for getting notification, if I press yes then the Device token is generated, but whenever I relaunch the app, I get the error:

Failed to fetch APNS token Error Domain=com.firebase.iid Code=1001 "(null)

Can anyone tell whether the device token is generated every time the app is launched?

Answer 1

Nope. A (new) token is not generated every time the app is launched. It is generated on initial launch (i.e. first launch after app install). From the docs:

By default, the FCM SDK generates a registration token for the client app instance on initial startup of your app.

But it may change because of the following scenarios (also from the docs):

The registration token may change when:

• The app deletes Instance ID
• The app is restored on a new device
• The user uninstalls/reinstall the app
• The user clears app data.