When a device has a 12V trigger input, it is designed to be turned on when a 12V is detected. You can use any standard male to male 3.5mm (3-pin type) cable.
https://components101.com/connectors/35mm-audio-jack
The Tip section is +12V, the bottom Sleeve section is GND, and the middle Ring section is not used. Nuprime’s trigger design uses 3.5mm stereo cable pin 1 and pin 3. A mono trigger cable shorts pin 2 and pin 3, it can be used to connect the Nuprime device to another device’s trigger that only uses a mono cable.