How to add cv::calcHist()

I’m on ubuntu and I’m using VSC, when I type cv::calcHist() it seems i dont have this function. How can I add it ?

this is very unlikely.
did you

#include <openv2/imgproc.hpp>


please also see tutorial

Yes I have mentionned all the includes like the tutorial.

then, please show, what you’re doing, and resulting errors