I don't find how to configure McIntosh MX121

I have McIntosh Mx 121 processor. I see, that Roomie supports it. But when I try to configure it, I don’t find it. I am trying to configure it using Serial port. Can someone help please?

McIntosh is on the infrared compatibility list:

roomieremote.com/ir-compatibility/

It is not on the serial compatibility list:

roomieremote.com/serial-compatibility/

However, if you have the codes, you may be able to add it using the DDK here:

roomieremote.com/faq/#customDevice