I did get the pigtail free from Tesla for my 2021 MY. It really should be included with the tow hitch option. But getting it connected and set up with a trailer brake controller under the dash is a bit of work. Instead, a friend has a Bluetooth brake controller (Curt 51180 Echo, available on Amazon) that plugs into the trailer light socket at the trailer hitch, then the trailer light cable plugs into the controller. Sensors in the controller detect braking and activate the trailer brakes. There's an app to adjust the braking force. A little expensive, but much easier to set up and use.
