Debugging openid connection via Java REST client

Hello, and thanks for the assistance, while performing Automated tests, i’m trying to imitate the way this open id connect debugger works: https://oidcdebugger.com/, i prefer to avoid approaching an external website.

So i’m using Java with regular rest client ‘OkHttp’ and sending GET request with the following details:

HTTP GET: https://dev-xxxxxx.okta.com/oauth2/aus30u5zv79pQrS9W5d7/v1/authorize?redirect_uri=https%3A%2F%2Foidcdebugger.com%2Fdebug&client_id=xxxxx&scope=openid&state=Test&nonce=1639303289&response_type=token&response_mode=form_post 

But i get in return an HTML page with the following error:

<span class="icon icon-16 icon-only warning-16-yellow"></span>You are using an unsupported browser. For the best experience, update to <a href="https://support.okta.com/help/s/article/Okta-Browser-and-OS-Support-Policy">a supported browser</a>.</div>

All i want is to get the log-in response json from Okta to read the details inside
anyone made such operation via java?

Thanks, Adi