I am having problems retrieving the expected response containing the access token, using these instructions: https://www.zoho.com/accounts/protocol/oauth/js-apps/access-token.html

In the responsive, I instead receive a Zoho login box that appears to want credentials. 

Maybe I am misunderstanding, but I was hoping to make an AJAX call to retrieve the access token, then use that token to make subsequent API calls. All this should be transparent to the user. Is this possible via JavaScript alone?