We have created a multi-tenant entra app which we want to use with our customers when they perform Oauth with microsoft. There are other tenants with whom this app has worked perfectly fine. But one of the tenants (let's say Tenant-A) is getting an error AADSTS900971: No reply address provided, even though we mention the redirect URI when using https://login.microsoftonline.com/organizations/oauth2/v2.0/authorize . Is this something to do with settings on their AzureAD? Also is there a way we could share some app URL with customer and get it whitelisted on their end by their microsoft admin? (Where can I find the global app URL if this is possible)
Additionally on the error page there's a warning at the bottom saying Warning, access to this system is restricted to authorised Tenant-A personnel only.
Closing this question, since issue was something else. The authorize endpoint was being called with some old app's client-id.