How do you add gearbox oil on a Peugeot 407 automatic?

To add gearbox oil to a Peugeot 407 automatic, first ensure the car is on a level surface and the engine is warm. Locate the transmission dipstick or fill plug, which is usually found near the engine. Use a funnel to add the recommended automatic Transmission Fluid through the dipstick tube or fill plug until it reaches the proper level, as indicated on the dipstick. Always consult the owner's manual for the correct type of fluid and specific instructions for your model.