Hi v-huizhn-msft ,

Thank you very much the info above and as per the requirements, i can confirm the below:

1. My organization is already using Azure Active Directory because from the results panel in "Reporting Services Configuration Manager", Singinging in to the Azure Active Directory shows success.

The problem is, i work in a very big organisation with dozens of AD domains under a parent domain managed at head quators. So i believe the Azure AD intergration is being managed at head quators because the admins of the child domain i belong to seem not to be having an idea of how Azure AD intergration came about. 

So if i have to talk to the admins at head quators, i will need to be specific on what exact permissions i want.

So do you know of any microsoft offical documetation that mentions exactly what permissions i need to be able to  register an app with azure active directory?

Do you know of a ste-by-step article on how to grant permissions in azure active directory?

On further research, i have come across this link https://docs.microsoft.com/en-us/azure/active-directory/active-directory-apps-permissions-consent  and the is a screen, with the "User Settings" link link highlighted which gives you an option to enable the "Users can register applications" setting. In my case all the optiions on that "User Settings" screen are disabled / readonly so i cannot click to enable them. Can i take it this is what the admins have to do to over come the error am getting?