An automatic leveling system for the Grand Design Reflection 337 trailer is not available from the factory. You'd have to get your dealer to install one aftermarket.
You'd have the choice of an electric lift system (easiest to install), a hydraulic unit with remote lifts and a system with separate hydraulic lifts on each lift head. You're talking about $5K with labor to install one.
I don't have a leveling system on my fifth wheel, however my campground sites are very level. If I traveled often, I'd have one.