Oauth2 Authentication with PKCE

My question: I am trying to get an access token using PKCE but unable to get the Login screen and the access token. Where can be the probable issue in access permission or POSTMAN settings? How resolve this?

My current authentication setup is like below:

  1. Custom identity server is implemented in dotnet core.

  2. Client request sent to my custom authentication server using Oauth2 where Grant Type is “Authorization Code (with PKCE)”.

  3. After clicking on “GET NEW ACCESS TOKEN” button in POSTMAN I am getting redirected to Azure ad login screen where two-factor auth is enabled and the second factor is done using Microsft Authenticator app in my case. The issue is I am getting the first screen to provide the user id(i.e. email id) but after clicking NEXT button I am getting a blank screen rather than getting a prompt to approve from my Microsft Authenticator app in my mobile.

I’ve already tried:

  1. I have verified all the scopes and credentials in the authorization tab with others for whom this is working fine. But for me and some new folks, it is not working.

  2. I checked the POSTMANconsole log and found that after clicking on the next button it is returning 302 status code and then 401 Status code.