Is there webhook to get notification about cancelled inapps in Google Play?

In my app, I need to handle cancelation of in-app purchases (not subscriptions) on the backend. In the best case, I'd like to get some notification when a user cancels in-app.

So I've found this API: https://developer.android.com/google/play/billing/realtime_developer_notifications . But this thing seems to be suitable only for subscriptions.

This API has sense: https://developers.google.com/android-publisher/api-ref/purchases/voidedpurchases/list . I can check it periodically, but this task can become too time-consuming as the count of users grows.

So is there some more clean way to get notifications about canceled in-apps? Or do I have to check statuses all the time?

from Is there webhook to get notification about cancelled inapps in Google Play?