Yes. The voltage must be matched, so 12V and 12V. The current required by your device, 3A must be available from the power supply, so a minimum of 3A. 5A gives you some headroom. So basically the V ratings must be equal and the A rating of the power supply needs to be at least equal to and ideally a bit higher than the A requirement of the device. (Don’t get carried away and have a 100A power supply on a 1A device.)
This just covers the specs, it does not say if the power supply is any good.