Whats a volcano stove?
Is that like a rocket stove?
See here:
https://www.happypreppers.com/volcano-stove.html
I don’t know if they show you, but with only about 12 pieces of charcoal and a dutch oven, you can cook a full meal in a pot.
After you see what a volcano stove looks like, go to Goodwill and pick out some nice stainless steel vegetable pots with all the holes in them. Make your own cooker really cheap.