I use a cable type bike lock. Before you go to the store, measure the opening in the metal tab. The first lock I bought was too big to fit through the metal tab.
Get something where the lock is as water proof as possible with rubber covers, etc. Last thing you want is to hook up your lock to keep your expensive EMS from being taken and then find when you are trying to leave that the lock is rusted shut...
2019 Globetrotter 27 FB
2018 Chevy Silverado 2500 4WD LT