That scenario occurs in the *Avatar: The Last Airbender* animated series, where Aang and Katara discover a door leading to the Southern Air Temple is blocked by rocks and debris. Aang sends Momo through the crack in the door to see what's on the other side, and Momo returns to inform them that the door leads to the Air Temple.
The game doesn't have this exact scene, and it focuses on different aspects of the story. However, there are many other elements in the game that allow you to explore the Air Temple and its surrounding areas.