How to wire a 3pin LASER on a MAKERBASE MKS DLC V2.0 board?

Hi !
I have a two trees laser engraver with a Makerbase DLC V2.0 controller board.
On it, the Laser got 4 pin : +12V , -12V , TTL-G , TTL-S
I want to upgrade it with a 20W laser from ORTUR with only 3Pin (I suppose +12V , -12V , and ???)
I don’t know if it’s possible.
Does anybody have an idea how I could plug it ?

Do you have any specs on the diode drivers interface?
BTW that is not 20W laser its 20W electrical 5.5V optical.
I guess they claim to have a 7W version now…

The diode is 5.5W optical (20W is written on it but it’s the electrical power)

Do you have any interface specs for the one you are upgrading to?
Likely the ??? is a PWM signal but the interface type would help.

Capture d’écran 2020-05-20 à 22.37.12
My old laser module (2.5W) have 4 pins.
My new laser module (5.5W) have only 3pins.

I suppose the 3 pins of the new laser module are +12v, GROUND and PWM+
So where do I plug de PWM+ ???
Thanks for your help.