Azure AD oAuth request returns html page and not oAuth Code

Hi all,

I'm new to PBI and the AAD world, presently working on an Embedded App Owns Data POC for our company, to display custom dashboard for our clients within our application.

I've followed all the step to declare a PowerBI Native App and grant permissions in our Azure Active Directory tenant, got a client id, the oAuth API endpoint. I declared urn:ietf:wgauth:2.0ob as a return url for now.

Since we developped our app in Ruby on Rails, I'm test riding the API with raw calls with the Restlet Client Chrome extension.

I'm following the instructions there : https://docs.microsoft.com/en-US/azure/active-directory/develop/active-directory-protocols-oauth-code

I am stuck on the first step. When I call POST on this url :

https://login.microsoftonline.com/"mytenantid"/oauth2/authorize?client_id="myclientid"&response_type=code&response_mode=query

I don't get a response with an AD access code but an html page that basically says "Connect to your application".

Any help will be greatly appreciated...

Thanks forward !