Level: First build

When components line up

Two LEDs in series. Together they need more than 3 V, so neither lights.

Open in the 3D builderReserve a kit
+−3V220Ω220Ω
Not runningNothing is running yetCurrent needs a complete loop from the battery's + to its −. Check the blocks touch, point the right way, and that any switch is on.

Try this

Remove one LED and replace it with a wire block.

Blocks you need