In my installation of Qt 5.14.2 using MSVC 2015, 64 bit, the include files are at 5.14.2/msvc2015_64/include/QtCharts, the libraries are at 5.14.2/msvc2015_64/lib, and the DLLs under 5.14.2/msvc2015_64/bin. My MinGW install has them in the same places relative to the top level of the mingw path.

If you are working on linux I can't tell you where they might be.