Black Myth: Wukong isn't a true Soulslike in the traditional sense, but it does share a few core elements players will recognize. Chief among them is the healing system. To recover health, The Destined One needs to take a drink from his limited gourd. Once you've downed the entire thing, the only way to refill it is to rest at a checkpoint. This makes rationing your drinks critically important, especially during boss fights. However, there is a way to upgrade your gourd to not only grant additional sips, but also apply new buffs. You can't do it yourself, so here's where and how to upgrade your gourd.
How to upgrade your gourd
There aren't very many friendly NPCs in Black Myth: Wukong but there is one you would be wise to find since they are the only way to improve your gourd.
Step 1: Follow the main path in the first zone of the game.
Step 2: Reach the checkpoint in the Bamboo Grove called Marsh of White Mist.
This will be right before a boss fight in a swamp, but you can come back if you've already passed this point.
Step 3: From the checkpoint, head forward and go down the wooden scaffolding along the cliff.
Step 4: Take the first right into the cave and speak to the monkey inside.
Step 5: Here you can perform various upgrades to your gourd for rare materials, including adding more sips, increasing the potency of your specific gourd's effect, and use him as a vendor.
This NPC will stay at this location for the entire game, so you will need to return to him any time you find upgrade materials and want to improve your gourd. Thankfully, this checkpoint will be marked once you have found him so you can easily go back to it.