put https://api.proof.com/v2/webhooks/
Updates a specific webhook by ID. If a webhook URL has already been set, it will be overridden. The new URL will be used to notify your application of state changes in any and all of your transactions. You must include a list of subscriptions for the events you would like to receive webhooks for. You may specify an optional header value for Proof to include in the callback. This could be something like an internal API key for additional security.