Are you malaysia? If yes, there are actually sold at certain place, not all place sell the halal version of miso. Usually it sell in place like big city or city like that.
because a lot of soy sauce in japan contains mirin, which contains alcohol. & as you might know, alcohol is also non-halal for muslims to consume.
so it's not the soya sauce that we can't eat, it's the mirin. most soy sauce from other countries, especially in south east asia doesn't contain any alcohol in them.
Wait, I know pork is haram for us muslims but why is soy sauce and miso there too? We dont have miso being sold where I live but soy sauce is and I've had it before Σ( ￣□￣||)