Navigate to “Manage Jenkins” => “Security” (In older version of jenkins it can be found as “Configure Global Security”)
Pre-requisites information:
1. LDAP server
2. root DN
3. Manager DN credentials (a service account credentials)
4. A security group for group level access
Select Security Realm as LDAP and fill the below information:
For Authorization, add your ldap security group.
Now click on “Test LDAP settings” and enter your ldap credentials. You should see below o/p
You can also check your authorization on: http://localhost:8080/whoAmI/
Reference: https://plugins.jenkins.io/ldap/
https://docs.cloudbees.com/docs/cloudbees-ci-kb/latest/troubleshooting-guides/cannot-make-my-ldap-configuration-to-work