How does Monster Hunter 3g connect the right joystick?

You must set a joystick. The PS2 version can not only move, but also attack with a joystick.

Both the left rocker and the right rocker must be set. If the attack is on the right rocker, the R3 key of the right rocker must be set. Without this crossbow, you can't shoot, the pike can't sprint, and the dragon gun can't shoot.

Take a good look. It should be possible. Up, down, left and right can only control the viewing angle. It is best to change a better handle, or directly connect a PS2 handle with an adapter. To tell the truth, most computer handles are not very good.