Here's a model of a key usually found in public bathrooms to open soap dispensers, but also toilet paper dispensers. I designed this for a friend of mine who works as a janitor in a school, hope you find it useful too.

Creality

Ender-3 S1 Pro

Yes

0.12 mm

100%

Highly recommend to use tree supports for the two hoverhang parts at the top, while printing it straight up. Also, try to remove supports from the hole as it should print without any problems.