When the back is open and the pin is released the counter resets to zero, so the door absolutely must be closed. It's sort of like opening a 35mm.
And the wheel digging into the backing paper is what turns the counter, you absolutely must have film.
And the take up spool MUST be snapped into the button on the left properly or it won't give enough pressure to engage the toothed wheeled. Make sure the spool is held firm. The prongs must be engaged on the spool properly.