The dripper should be positioned on top of or hung above the enclosure. You will have to stretch a hole in the screen to allow the tube to come into the enclosure. I secured the tube with a twist tie to a branch above some other branches and leaves.
There is a control valve on the dripper so that you can regulate flow. About 2 to 3 drips per second is what I do.
Letting some drip down will tell you where it will fall on the bottom of the cage. If you do not have a drainage system you will need a collection bucket. I use a one gal. bucket with netting stretched over the top with a rubberband to keep crickets, roaches and my cham from falling into the water.
In the morning I empty and replace this collection container and fill my dripper. The little dripper will go for about 6 hours and the big dripper even longer. My cham drinks right out of the tube gulping water like you would drink from a garden hose. It takes them very little time to figure out this system and it provides drinking water for most of the day if not all day long.