This page describes webhook action in more detail
The webhook action can be used to invoke any third-party REST API and sends the sample in the request body.
The HTTP method, multiple custom headers, content type, and authentication method can easily be specified.
Authentication flows (e.g. Oauth2) are not yet supported.
The whole sample will be forwarded to the invoked endpoint. Make sure you trust the API in question and don't include sensitive data in the sample.