how to make coffee in one hour

take a tin, a bin

but any cylinder shape metal drum will do

1

2

cut a hole, where you're going to feed the fire

should be towards the bottom of your drum, but a good few centimeter above ground

3

insert a metallic cylinder shaped tube in your new made hole
should be fitting just right

4

think of some solution for the top, so when you put your pan on the fire it won't block the air going in your rocket stove to feed the fire

one of the simplest solution, cut in the top and fold the half in

like that