How do you make popcorn in a steamer?

Based on the reference provided, here's how you can make popcorn using a steamer, assuming it's a microwave steamer:

1. Place popcorn kernels inside the microwave steamer.
2. Put the steamer into the microwave.
3. Use the microwave's popcorn setting, which typically runs for around 3 to 3.5 minutes.