How to implement Webhooks in HubSpot, and how do they differ from an API?

Hi, I am trying to use the “Trigger a webhook” bot action in a Chatflow to integrate it with an external bot which will use NLP and have other functionalities. I want to respond with a message in the webhook response. However in HubSpot documentation for working with bots here - it only shows an “Example response payload” with “botMessage” field as null.

So apart from a simple text message as a “botMessage”, are there other fields that are supported for a webhook response? I have tried “quickReplies” and it works. Would be nice to have a documentation with all the supported fields.
Also the external bot supports Quick Replies that open a Url on click, sending and receiving images/files, and also sending rich cards. Would like to know if any of these capabilities are supported for HubSpot bot, specially a QR that opens a Url link.

Thanks.