What is dripping from the bottom of your Urban Worm Bag is called leachate and it is the result of your organic waste releasing water as it decomposes.
Leachate seeping out of the bottom your Bag is normal in the first few days when the moisture in your initial bedding is settling out. In this case, this leachate is simply from excess water in your initial bedding layer that is settling out.
But on an ongoing basis, you do not want leachate seeping from the bottom of your Urban Worm Bag. It indicates overfeeding or feeding too much food waste without adding bedding to absorb the moisture. If the bottom of your Urban Worm Bag has a zipper, it will eventually foul up the teeth of the zipper.
If your Urban Worm Bag is dripping, you will want to open the bottom zipper or fully remove the bottom (if you purchased after March 2021) to release the excess moisture and stop feeding.
You should also consider stuffing absorbent material like paper or cardboard up through the bottom of your Urban Worm Bag to absorb the leachate.
Most vermicomposters underestimate the amount of water that is stored inside food waste and as the food waste breaks down, this water is released into the vermicompost. Adding water is often unnecessary, but if you must add water, then you should add it by spraying, but not pouring water into your Urban Worm Bag.