We're unable to complete your request invalid_request: The provided value for the input parameter 'redirect_uri' is not valid. The expected value is a URI which matches a redirect URI registered for this client application. When working in Dot Net Core 2.2 and would like to authenticate users using external Microsoft Account you might get an error that says: We're unable to complete your request invalid_request: The provided value for the input parameter 'redirect_uri' is not valid. The expected value is a URI which matches a redirect URI registered for this client application. Possible Solutions during Configurations in Microsoft Azure Make sure you follow this documentation here In your Azure account, navigate to Azure Active Directory and create/register an App Under "Redirect URIs" make sure you type in the domain name (if the app is still in development:type in https://localhost:{portnumber}/signin-microsoft) This is important step or else you will experience trouble login in.  Scroll down on the Authentication page (Same page as Redirect URIs) and check the ID tokens checkbox and toggle the Live SDK support button. On top of the page there is a Save button, save your configuration and move on to the next step. At this time, when you attempt to test the app for external login, you will have an error, instead, navigate to "Certificates" and create an App-Secret Key that you will use in the Development process according to official documentation given on the link above. Don't use the Object ID: as an App-Secret Key, if you do, the authentication will not work.