Suggestion: Always find in the documentation the name you are supposed to use
BoxWhiskerChart
Remember that Mathematica is completely unforgiving of any tiny error in capitalization or spelling of a function name.
Then see if you can get your Mathematica to do the simplest example from the documentation. If it doesn't work then, character by character, track down what any tiny differences are and correct those. Then a bit at a time try to modify the example to match what you really need to do.
