For testing your board remove a jumper before connecting to power.

Check if no short circuit on power terminals.

⚠️ IMPORTANT: If you have a 5V power supply set it to 5V and if you have a 12V or 24V power supply put it to 12V ⚠️ Place power selector jumper back in position regarding of your power source (5V or 12/24V). Connect power supply and check if there is a voltage on pins 5V and GND. To do this place two jumper wires (or other type of wire) into a header.

If all steps went fine you can place your board on shield.
⚠️ IMPORTANT: Pay attention on board orientation and pins placement. Here is reference images ⚠️

After you correctly placed your board on shield, you can powered up and connect LEDs of your choice.