I would like to specify additional manual custom fields to outgoing web hooks. When I trigger the webhook, I would like to be prompted to add values to those fields, and then they would be included in the webhook payload.

Use case:

I'm working on an integration to our swag provider. I would like to be able to select a member, trigger the "Send Swag" webhook and then be prompted to enter a dollar value and a reason. The webhook would fire with those custom fields in the payload and it would be be recorded as a note saying something like something like "Sent $35 of swag to say thanks for the great meetup demo."