Connect an IR Rx with an IR Tx

I have an Wyrestorm MX-0402-STD video matix , and some EX-1UTP-IR-40 extenders.
My problem is how to connect the IR Tx cable from the extender to the Rx matrix connection.

I would appreciate if someone tells me how to do this wired connection (3.5 Mono to 3.5 stereo connexion).

Thank you very much.