AD FS OAuth
You need a working AD FS server. See the AD FS documentation and AD FS deployment guide.
Enable OAuth confidential client in AD FS
Follow Enabling OAuth Confidential Clients with AD FS to register an app and obtain a client ID and client secret.

Use the client identifier as Client ID and the secret as Client secret in Casdoor.
Add the provider in Casdoor
Providers → Add. Set Category to OAuth, Type to AD FS. Enter the Client ID and Client secret from AD FS.
