DsGetDcName

[DllImport("netapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern uint DsGetDcName(
   string ComputerName,
   string DomainName,
   Guid DomainGuid,
   string SiteName,
   uint Flags,
   out IntPtr DomainControllerInfo
);

Microsoft documentation: Link