We have a “WebHook Only” app.
How can we connect other accounts to it?
As far as I can see there is no way to publish it or even share an url to the (private) app so other accounts could authorize and install it.
What is the best way to connect other accounts so we could start receiving data from other accounts?
Is there only way to do it is to create a WebHook Only app for each account and setup it (same subscription settings, endpoint, event types…)?
Are these other accounts outside of your organization? You could create a public OAuth app with the event subscriptions you’re looking to receive data on, publish the app and have the external accounts install it. This would allow you to receive event-related webhooks. Although, this route will require a comprehensive process subject to our marketplace app publishing guidelines.
Alternatively you would different apps for each account that is subscribing to the events and have them sent to the same url.