Not able to add system

Dears,

I want to add one DMZ server in my TPAM device.

Steps i have followed:-

create a local account ppmuser in DMZ server.

Given the administrator rights to the ppmuser.

When i tried to add system in the TPAM it is showing the error "test system is failing is due to the computer name mismatch"

I have gone through the below documents and change the setting accordingly but still the same issue is happening.

Error: "Test system is failing due to computername mismatch. Please verify the expected computername." when testing system (225606) (oneidentity.com)

I have one doubt:- When i add the system in TPAM. in the platform do i need to add windows or windows active directory.

 I didn't configure the active directory in my server.

Can anyone help me with this?