It seems like you're asking where to place the cleaning solution in a foam cleaning gun.

Here's how you typically use a foam cleaning gun:

1. Fill the Reservoir: Most foam cleaning guns have a reservoir or bottle where you pour the diluted cleaning solution. This reservoir is usually located near the handle or at the top of the gun.

2. Attach to Water Source: Connect the foam cleaning gun to a water hose or tap, depending on the model. This allows the gun to mix water with the cleaning solution to create foam.

3. Adjust Settings: Some foam guns have adjustable knobs or settings to control the amount of foam produced and the spray pattern. Adjust these settings according to your cleaning needs.

4. Apply Foam: Point the nozzle of the foam gun at the surface you want to clean and pull the trigger to release the foam. The water pressure from the hose or tap will mix with the cleaning solution, creating foam that adheres to the surface.

5. Work in Sections: Work in sections to apply foam evenly across the surface. Allow the foam to dwell for a few minutes to break down dirt and grime.

6. Rinse: After allowing the foam to work, rinse off the surface thoroughly with clean water to remove the cleaning solution and loosened dirt.

7. Dry and Finish: Dry the cleaned surface with a microfiber towel or cloth. Follow up with any additional detailing or protection steps as needed.

8. Clean and Store: After use, clean the foam gun according to the manufacturer's instructions to maintain its performance and prevent clogging.

Always follow the specific instructions provided with your foam cleaning gun for the best results and to ensure safe and effective use.