LsaAddAccountRights

[DllImport("Advapi32.dll", SetLastError = true)][return: MarshalAs(UnmanagedType.U4)]
public static extern uint LsaAddAccountRights(
   IntPtr PolicyHandle,
   IntPtr AccountSid,
   LSA_UNICODE_STRING[] UserRights,
   uint CountOfRights
);

Microsoft documentation: Link