Tik-Tok the Mechanical Man (Dorothy and Tick-Tock)

Dorothy is on her Kansas farm. She looks up in the sky and sees a magical light. The next day outside she finds a key with the letters "O" and "Z". Upon examination, the key transports her to Ev, a magical land across the Deadly Desert from Oz. She is then chased by a group called Wheelers up a mountain. She finds a door at the top of the mountain.

Synopsis excerpt via Kitsu.