Hello
When creating an instance, you must create an application partition with a distinguished naming format, you can look at the following registry key "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\ADAM_instance1\Parameters", then look at the value of "Configuration NC" and try to connect to it.
You can also go to the CN=Partitions container to find other NCs in this AD LDS instance, right-click it and click New Connection to Naming Context, which will connect ADSIEdit to that NC.
NDNs in ADLDS have GUIDs as their DNs (as seen in the "Partitions" container)
Best Regards,
Wesley Li