How to fix "AADSTS90102: 'redirect_uri' value must be a valid absolute Uri." error in Microsoft Graph

Question

Following this procedure: https://learn.microsoft.com/en-us/graph/auth-v2-user

I'm trying to get a refresh token from this microsoft end point: https://login.microsoftonline.com/{tenantId}/oauth2/v2.0/authorize

Using PostAsync method from System.Net.Http.HttpClient class from nuget (asp.net core 2.2) library, I'm able to get a response back with this error: "AADSTS90102: 'redirect_uri' value must be a valid absolute Uri.":

I tried to set some redirect url in the Azure Portal including: https://automation.legroupeti.com/Configurations/GetRefreshToken/ https://automation.legroupeti.com/Configurations/GetRefreshToken https://automation.legroupeti.com/ https://automation.legroupeti.com

The post request is the following (Using PostAsync method from System.Net.Http.HttpClient class from nuget (asp.net core 2.2)):

Here are the configured redirect urls form the registred application in the Azure Portal:

I expect a valid response from the endpoint. How do I configure the redirect_uri to be valid?

EDIT 1

I fixed the redirect_uri parameter.

Answer 1

You seem to be mixing the authorize and token endpoints.

If you want the user to authenticate, you have to redirect the user to that URL, not send a POST request to it. After the user returns to your app, you need to exchange the authorisation code for tokens. Documentation: https://learn.microsoft.com/en-us/azure/active-directory/develop/scenario-web-app-call-api-overview

If you want a token just for your app without user authentication, you need to call the token endpoint. Documentation: https://learn.microsoft.com/en-us/azure/active-directory/develop/scenario-daemon-overview