https://en.wikipedia.org/wiki/Hero_of_Alexandria?wprov=sfla1

A vending machine that dispensed a set amount of water for ablutions when a coin was introduced via a slot on the top of the machine. This was included in his list of inventions in his book Mechanics. When the coin was deposited, it fell upon a pan attached to a lever. The lever opened up a valve which let some water flow out. The pan continued to tilt with the weight of the coin until it fell off, at which point a counter-weight would snap the lever back up and turn off the valve.

https://historyfacts.com/science-industry/fact/the-first-known-vending-machine-dispensed-holy-water/

Because vending machines are now automated, they can feel like a relatively modern invention. However, the basic contraption has actually been around for more than 2,000 years. Introduced around the first century CE by Greek engineer and mathematician Heron of Alexandria, the first vending machine didn’t deliver snacks — it dispensed holy water. Similar to modern machines, Heron’s device required inserting a coin into a slot. The coin fell onto a pan that was connected to a lever, which opened a valve on the other end where the holy water flowed out. The pan continued to move under the weight of the coin until, eventually, the coin slid off. The lever would then raise back to its initial state and close the valve, stopping the flow of water.