Credits: ZorroCraft 2.O
First, you need to create a vessel capable of carrying water. Luckily the addon introduces the Canteen. Go to any water source and fill it with water, but don't drink it yet.
The next step is to purify the water by putting filled Canteens into the campfire. After some time, the water will be boiled and you will get Purified water.
But care with how much you drink, because it turns out you can overdose with water.
On top of everything else, the addon also introduces a pack of matches, that can be used to light things up.