If you can't find coconut flour, you can make your own. Just grind unsweetened dried coconut in a coffee mill, mortar and pestle, or blender (small amounts at a time.) That's what I do, since my local stores don't carry it.
If you're allergic to coconut and other nut flours, there are substitutes, including tapioca. Few are a 1:1 ratio. Blends may be needed. I looked around and found this.
If you would like me to search further, I'd gladly do so.
Edit: If the coffee mill is used for coffee, clean it thoroughly. You may still need to toss the first batch to avoid the coffee flavor.