Supports

Supports are required with overhanging models to build up a print surface for the print head.

I would always recommend tree supports instead of wall. With tree supports, they are much easier to pull off the model and don't tend to leave any defects on the print. If the model you are printing is a 3mf and includes print preferences, leave supports on. Sometimes the model's designer will manually paint the supports. Although I have found auto to be very good most of the time if supports have not been configured.