Ldap authentication type "none" configuration issue

Situation:
I want to use LDAP( ActiveDirectory) authentication from keycloak.
The authentication type is set to “none” ( Anonymous)
I set the Users DN as follows —> OU=Ext,OU=X117,OU=ID,OU=Data,DC=example,DC=com

And the error i get is tho following

15:20:28,286 ERROR [org.keycloak.storage.ldap.idm.store.ldap.LDAPOperationManager] (default task-193) Could not query server using DN [OU=Ext,OU=X117,OU=ID,OU=Data,DC=example,DC=com] and filter [(&(cn=testuser)(objectclass=person)(objectclass=organizationalPerson)(objectclass=user))]: javax.naming.NamingException: [LDAP: error code 1 - 000004DC: LdapErr: DSID-0C0907E9, comment: In order to perform this operation a successful bind must be completed on the connection., data 0, v2580]; remaining name ‘OU=Ext,OU=X117,OU=ID,OU=Data,DC=example,DC=com’

When I set the ‘simple’ authentication method and using my user

CN=testuser,OU=Ext,OU=X117,OU=ID,OU=Data,DC=example,DC=com

Then everything works as expected.
So i assume that I must modify the users DN field in a way to append the CN=“username” dynamically during execution time, as a prefix but I have no clue on how to do it. Any hint would be much appreciated!

Can anyone give me an example of how to configure my ldap given that the

  • “bindType” = none

  • and the user DN is —> CN=testuser,OU=Ext,OU=X117,OU=ID,OU=Data,DC=example,DC=com