Create object to pass into myscada function. This object must have 2 parameters data and areaId. For how to construct data parameter, please consult online manual for chart.js library. When createChart function is called, myscada will automatically create canvas in the place of active area. Into this canvas is the chart rendered. So you pass only second parameter eg. data to the chart.
4. We need to specify to which active area render the chart.