Unable to get the authorization code

Hi,

We have registered an application under “API Applications” and got the “Client Id” and “Client Secret” to access the API. But we stuck up in the initial stage itself to get the “Authorization Code”.

Based on the following example, we try to get the authorization code with all the needed parameters using the following URL.

https://secure.eu2.adobesign.com/public/oauth/v2?redirect_uri=https://secure.echosign.com/public/login&response_type=code&client_id=C**********A-*****************S&scope=user_login:self

As mentioned in the above screenshot from the document, in the response we neither get the authorization code nor the error. Instead we receive a HTML of the following page.

Can anyone please help me out to get the authorization code?