The limit is the number of amps, 32 in this case. Running that on 240V gives 7680W, or 7.6kW. Very often the voltage you get at home, especially when pulling 32A, will drop to something lower. I've seen 228 when pulling 48A on mine. 228*32 gives 7296W, or 7.3kW. The charging speed will vary a bit depending on your voltage drop.
To get to kph, which is a weird measure for charging IMO, you need to use your car's energy consumption constant. I'm not sure what these are on the current models... From your TeslaFi information it appears to be 135wh/km. With that value, you would typically charge between 54 and 57kph.
You could arrive at 48kph if you used a higher consumption constant, like 152wh/km for example. (Note: my 2020 LR AWD uses 146wh/km I believe). As the cars evolve and some things get optimized, Tesla might not always update those tables that show the charging speeds depending on amperage. The important thing is that your car pulls up to 7.6kW of power in AC charging.
EDIT: I just realized that I forgot to account for power usage of the car while charging as well as charging losses. I don't have those values precisely. I know the car consumes something like 200W to be awake and run the pumps so at a minimum there's 200W less that goes into the battery. If it was 90% efficient, I think you should remove ~10% from that power... you might end up with 6.7kW in the battery in the best case, which would be 50kph. Since you're getting more than that, I will assume the car doesn't account for losses and reports input power
