A user defined value which can be used for reference purposes in the webhook. This may be useful as an additional context value for lookup purposes in addition to the subscription identifier, and as an added layer of security for verifying the source of the webhook caller.

The time interval for callouts made to the webhook, i.e. the time which will at least pass between two webhook “Notifications” callouts for a given subscription. For example, when specifying 300 seconds, Unity API will at least wait 300 seconds before calling the webhook of new notifications again. Set to 0 if the webhook should be called as soon as possible when new notifications become available.

The URL of a publicly accessible API function (the webhook) which should be called by Unity API to confirm the webhook subscription and to inform about the availability of new notifications (must be an HTTPS endpoint with a fully qualified domain name and a valid certificate).