MTC, on a MIDI port
MIDI Time Code, for audio workstations and receivers that prefer it.
The MIDI port is named by its name, never by a number. Ports renumber themselves when a controller is plugged in, and a show reopened the next day would then aim at another device without saying so.
On a machine with no physical MIDI interface, a virtual port does the job — loopMIDI is the most common. The walkthrough has its own guide.
MTC output is granted from the Booth plan upwards.