Can I skip the mirin when cooking Hoba miso?

I bought a miso paste from Japan. Want to use it now with some beef and mushrooms, but just realized I don't have mirin that's needed for the miso mixture.

Google told me there are possible substitutes for mirin but I also don't have those ingredients on hand, and I don't really feel like going out right now to do some last minute grocery shopping.

I'm thinking of just skipping the mirin altogether and using the miso paste as is. Is that a bad idea? Not sure if that would make it too salty.

Photo of the miso paste instructions included on here if that helps. It says it already has mirin on there, so maybe I don't need to add more?

Thanks so much to anyone who can give some advice.