That's frustrating! I understand your disappointment with the lack of clear instructions. I've found these flow sensors can be a bit fiddly. Unfortunately, I don't have specific calculations for those nozzle sizes. In the meantime, while you're waiting for official support, you could try running some water through and timing how long it takes to fill a known volume container. Or, for a quick distraction during the troubleshooting, try playing the Dinosaur Game ******, it's a classic! Hope you get it sorted soon.
https://dinosaurgamefree.com/