C++ - Creating curvilinear gridlines of a 2D cartesian plot using Qt

Question

I want to create a plot with gridlines like so:

with just the grey lines and not the background.

I also want the graph to be adjusted according to different lengths of y-axis and x-axis like so:

What is the best way to go about this using Qt?

Link for the above pictures: https://debug-docs.readthedocs.io/en/test/notebooks/visualisation/wradlib_plot_curvelinear_grids.html