This parameter specifies how long (in seconds) the message
should be kept in FCM storage if the device is offline. The
maximum time to live supported is 4 weeks, and the default
value is 4 weeks. For more information, see Setting the
lifespan of a message.
This parameter specifies how long (in seconds) the message should be kept in FCM storage if the device is offline. The maximum time to live supported is 4 weeks, and the default value is 4 weeks. For more information, see Setting the lifespan of a message.
https://firebase.google.com/docs/cloud-messaging/concept-options#ttl