Update Webhook of Custom App

I created a Dedicated Attached Webhook for a Instant Trigger module of my custom app.

How does the Update part work? I tried the same code like for my Attach logic, but it is never called.

I wish to let the customer edit the Instant Trigger Webhook.

When I put my Parameters in the Webhook then they can be configured once, but never edited. The edit function of the Webhook in the scenarios is greyed out.

When I put my Parameters in the Instant Trigger Module then they are editable in the module of a scenario, but the edit does not have an effect on the Webhook.

None of the example apps is using the update functionality.

The documentation on the Webhook Edit Page says:
“Describes the API call to be performed when a scenario containing the Webhook is published. Leave empty when there’s no such call. This specification does inherit from base.”

The documentation of the VS Code Extension says:
“Describes the API call to be performed when the webhook is updated. Leave empty when there’s no such call. This specification does inherit from base.”

None of both seems to be true.

Did anybody manage to use the Update functionality of webhooks?

Thanks in advance for your help!