Unfortunately, it comes with the usual drawback of cheap Chinese stuff: no instructions. The visible pots are straightforward enough, but the Z- axis and the button are connected through wires. I have one red, one black, one white and two blue ones coming out of the joystick. Do you know which one goes where?
Three of the wires are connected to the z-axis pot. You can use an ohmmeter to find the wiper.
On my joystick the black wire is the z-axis wiper.
The red wire was the pot’s Vdd.
The blue wire which measures 5k (of whatever value the pot is) between itself and the read wire is the pot’s ground wire.
The blue wire with infinite resistance between it and the red wire is the button wire. When the button is pressed,
the two blue wires are shorted together the blue button wire is shorted with the white wire.
I added a six pin connector to my joystick.
I joined the three Vdd pins together and connected these to one of the six pins. The grounds were all connected to a second pin. The three wiper each had a pin and the button wire was connected to the last pin.
The ground and Vdd positions on the two lower pots are arbitrary. I wired them in a way which would give larger analog values as I moved the joystick to the right and up.
The button pin is pulled high by the Arduino and when the button is pressed, the button wire gets connected to ground. This makes it an active low button.
It would certainly be possible to wire the button so it’s active high. This would require swapping the Vdd and ground lines to the z-axis pot and using a pull-down resistor on the button line.