BI events related to charges have been replaced by the External Billing Events API. Use this new API to report your app's external billing events to Wix.
This API allows 3rd party apps connected to Wix, to send BI events to the Wix system. It includes several out-of-the-box events, like when the app dashboard is loaded, or when a primary action is taken (the most valuable action in an app product flow). If the list of built-in event does not suit your needs, you can also send a custom event.