Here's how to solve it:
1. Use "Wingardium Leviosa": This spell will allow you to levitate objects.
2. Target the banana: Use the spell to lift the banana into the air.
3. Move the banana over the bowl: While the banana is levitated, carefully move it over the top of the fish bowl.
4. Release the banana: Once it's positioned directly above the bowl, release the spell. The banana will fall into the bowl.
This puzzle is a bit tricky since the banana is on a ledge and you have to maneuver it carefully. You might need to use the spell multiple times and adjust the banana's position to get it into the bowl successfully.
Let me know if you have any other Harry Potter game puzzles you need help with!