You'll find that you need Fizzy Crystals to make any recipe in the Soda Machine. So, if you don't have any on you, you need to get some before you can continue this quest. When you've got a Fizzy ...

I count 24 days until Monster Hunter Wilds is out. That's close enough that I'd recommend going on a full promotional blackout until you can play it yourself, but if you're already here ...