It depends on the inrush current of the motor.
The inrush current can be upto 10 times the running current.
Also the stall current can come into play.
Take a look at the datasheet of the motor you are going to use.
The stall current maybe the 2A maximum shown, if you need to confirm the initial or stall current it can be done with a variable supply to apply a small voltage to the motor with a locked rotor while measuring the current to obtain the resistance.
Do not measure resistance directly if this is a DC brushed motor, it is not accurate enough.
Max.
The link brings me to a selection of 12V supplies with current ratings up to 30A.. You didn't specific exactly which one you wanted..
And based on some other Chinese power supplies I've bought in the past take the current rating you need and double it..
Those typically run much hotter than a "quality" supply and I'd never run it anywhere near its max rating..