how to automatically link identity to Active Directory

You need to assign the account definition to the identity automatically if you want to automate this. There are several ways of doing this, see https://docs.oneidentity.com/bundle/one-identity-manager_connecting-to-active-directory_9.3/page/sources/ads/adtsbaccountdefassigntoperson.htm

Think of an account definition as an account creation task, that does nothing on its own. The task has to be assigned to the identity to tell the system, please create me an account for this identity based on the definitions you have configured in this account definition.

Thank you

Thank you