NEMA 6-20 Extension Cord 6-20P to 6-20R for Tesla Mobile EV Level 2 Charging Heavy Duty 250 Volts 20 amp 50FT ETL Listed

Pretty easy to find those too. Since you haven’t said what amp you are looking for here is a 20amp one as an example, 50ft for $80 https://a.co/d/0eR7L6Uo