How do I get my custom block to render the sides not facing me?

Hi,

So I made a custom flame block, but it doesn't render the sides not facing towards me.

I've set the block model json "ambiance occlusion" to false, no cullface, and in the block properties page set the transparency to cutout.

I want it to act like the vanilla flame but with extra functions. What else do I need to do? What am I missing?

A