Redirect URI to aspx webform

Hi, we have a legacy webform (framework 4.5) application. We are trying to implement AUTH0 as SSO provider and Azure AD as IdP. The app is registered on Auth0 and the connection to AAD works fine. The issue is the callback URI (RedirectURI) points to an aspx page (say https://localhost:3000/default.aspx) and that redirect does not happen post authentication. The same setting for an MVC app with callback set to an Action method works perfectly fine, without any issue. My question is, has anyone made the similar set up work for ASPX pages? If so, can you share some insight? Thanks in advance.