Bena.
Canaries, nice, lots of volcanic stones which are refractory.
You can make something along the lines of the lorena or ecofogao. I don't know if you have refractory clay chimney elements in the Canaries. This is what the ecofogao uses, and would be simplest. There's one thing about this later one, i find the heat riser too short.
Metal plate, you can find from an old discarded wood or coal range or stove.
Crush some pozzolan, or pumice, to mix with "ciment fondu" And you're sorted for your refractory binder.
You can make your plans yourself. Or search in there!
https://3dwarehouse.sketchup.com/search.html?backendClass=both&q=rocket%20stove
did you see this one?
Or you can go my route!
https://permies.com/t/35569/Range-retrofit