While reverse proxy CAM applications will send whichever HTTP verb the backend application requires (PUT, POST, GET) only the non-proxy form fill option will send an unsolicited POST direct to the Form Action URL, bypassing the Login form entirely. This lack of reliance on a form means it can theoretically be used to send an unsolicited POST to any URL. Suitability for use against a particular application will need to be tested locally and can’t be guaranteed.
To set up a non-proxy form fill application, you would setup a form fill app as normal but on the page where it asks you if you want to proxy the application, say no; static parameters can be set as query string parameters in the URL and/or attributes from AD can be sent as HTTP headers.