That chart is showing all cars (not just electric); BYD is too small a part of the market to show up right now. Same with GWM/Ora, possibly due to calling their first Europe-targeted car the "Ora Good Cat" (sadly, they eventually hired someone who had at least heard of marketing, and it's now called something boring). SAIC is there.
Chinese electric cars are available here, but not, as yet, particularly popular.