This is a difficult one to answer since every Air Fryer model is different. The consensus seems to be to soak the basket, and removable bucket in warm soapy water for around 10 minutes before trying to clean it. Don’t use any scouring pads that scratch because the Air Fryer bucket is usually non stick and a scouring pad will in some cases peal off the non stick coating. From personal experience, you can also place the parts into a dishwasher but I would still soak it in soapy water for 10 minutes first so you can remove as much grease and grime as possible before placing it in the dishwasher.
Personal experience from using the Philips Airfryer XL though is that over time no matter how much you clean the parts, they will eventually be impossible to clean. The grease tends to really set and become a nightmare to keep clean. Having said that, other people may get different mileage as I tend to not clean it all the time.