>>105804231
there are a bunch of 3d printed 5$ ones on aliexpress that have a potentiometer, a usb-c port, and a 4 pin pwm port, you can also find them dropshipped on amazon for 3x the price (as always)
these work with any 5v1a usb phone charger (it has a 5-12v booster circuit built in)
you can also find 12v DC barrel jack to 4 pin adapter cables for like 2$ in case you don't care about the potentiometer and have a power supply from an old router laying around
a bunch of usb-a ones with a simple switch are also available, you get the idea.