NEMA L14-20P to 14-50R 120V/240V 20 Amp Twist Lock 4 Prong Plug to 4 Prong Female Outlet Receptacle Generator RV Welder Dryer EV Charger Power Cord Adapter

This plug uses a L15-20, but it has the same plug layout as L14-20 No it isn't. They're slightly different to prevent insertion of an incompatible plug, e.g. it would be extremely destructive if a 120/240V load were connected to a 15-20. They're not keyed differently to annoy you, they're keyed differently to save your dumb ass. Don't defeat that. Here's the L15-20 adapter for your Tesla Mobile Connector https://acworks.com/products/g2evl1520pt-16a-nema-l15-20-to-gen-ii-tesla-mobile-connector?srsltid=AfmBOopp4YYQIIu6frn-FCJprcv05oV82kOVV8ZkjZ4VrQu4U0zZ992f L14-20 on Amazon L15-20 on Amazon Thank GOD you asked for our advice prior to doing any of this stuff. YOU DO NOT simply mash together plugs using rando Chinese adapters, because of the stuff I covered in paragraph 1. Not least, your charger would try to pull 32A off the circuit, and your reward would be a breaker trip at best or a fire at worst, depending on how well the circuit is wired.