This method registers a callback function as an event handler. Subscribe your app to the relevant event via the Webhooks page in the Wix Dev Center to enable it. For more information, see Handle Events With Webhooks
When developing websites or building apps with Blocks, use Velo backend events.
Triggered when a Wix user cancels a paid plan for your app. The
Wix user can continue to use your app until the end of the current billing
cycle.