A super simple circuit is to use an OptoDarlington such as a TIL 197. It’s a 4 pin chip so all you need to do is to take the LED output from the board and feed it via a suitable resistor into Pins 1 & 2 (which is essentially an LED) then attach Pin 3 to the lamp supply ground and pin 4 to the lamp negative and the lamp positive to the +12 supply. The chips also come in a 2 way and 4 way package - TIL 198 & TIL 199.
This has the advantage of completely isolating your Arylic board from the lamp circuit so could reduce potential supply interference from the 12v side.
PC817, PC827 or PC847 optocouplers with transistor outputs may be better suited as I don’t know the spec of the lamps you have but they are pin to pin compatible with the TIL197 types. If you need more power then these optocouplers will replace the transistor stage in stewc’s circuit quite nicely and give the benefit of isolation.
ULN2803A is a also a pretty useful chip for these applications but are not opto-isolated and you may need to invert the logic going in with some NOT gates but again, very simple to use.