Basically, you need your Active Directory computer’s details and need a service account to connect the AD.
First part of LDAP is to type correct server name and define the port number to be connected. 389 is LDAP Port, If you have configured LDAPS before, you can use 636.
Second section of LDAP is to write correct user details. No special membership is required for this section.
If you adjusted the attribute of AD before, you must type correct values here. I never changed it before and I never touched this section too.