The macOS C++ binary in our web site is already a universal binary for i386, x86_64 and arm64. I think we updated it last Tuesday. As we are quite busy last week, we have not updated our web site yet, so it does not mention it is updated.
Please download the ChartDirector for C++ for macOS again. The libchartdir.6.dylib inside should contains 3 architectures as mentioned above.