@suslucoder As the error message tells you addSeries takes a QAbstractSeries, not a string list as parameter. You have to pass it one of the QAreaSeries, QBoxPlotSeries, QCandlestickSeries, QPieSeries, and QXYSeries.
You also should tell us what data your file actually contains? If it contains x/y values then you first have to convert the data to numbers and create a QXYSeries instance and fill it with that data (https://doc.qt.io/qt-5/qxyseries.html#append).