How POST request from client-side directly

[Alexandre Machado]

If it can't go through your server and must come from the browser, then yes, the only language that the browser executes is JavaScript,nothing else.

however, you can have help from IW code and your Delphi code and craft the request in your server, send it to be executed on the browser.

I'll see if I can create something simple for you showing how the basics work, but it will be far from complete for your specific case. The token exchange sequence used in general by these servers can be way more complicated.