Well the laser output socket appears to be the white one ( 2 pin) between the red and the yellow 3 pin to me....it says LASER alongside it.
I looked up the board and the connections are as follows. Red 2 pin is fan control
. White plug 3 pin is laser control. and yellow 3 pin (Bare) is for servo motor control. as in RC servos.
2 axis control panel board for DIY laser engraving cutting machine. Size: 94mm*46mm*21mm. Control software: bitmap print Version (Benbox) / advanced knife engraving (GRBL),support GRBL0.9,PWM control laser power.. Support steering gear control
.Power interface: DC 5.5-2.1 interface. Power supply: recommended to use 12V 2A DC power adapter (100-240V). ADJ module. Dual Y axis interface, can drive 2A 4 phase 2 wire stepper motor. MINI USB interface. Laser voltage adjustable. Fan interface
. Weak laser switch. also did you get all the mini plugs and usb cable that should have come with the board as in the picture.