I have been struggling with the same linkage issue while trying to use QCustomPlot, and the following setup in my CMakeLists.txt helped resolve it:

find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Widgets PrintSupport)
find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Widgets PrintSupport)

...

target_link_libraries(QCustomPlot_temp PRIVATE
    Qt${QT_VERSION_MAJOR}::Widgets
    Qt${QT_VERSION_MAJOR}::PrintSupport
)

Using Qt${QT_VERSION_MAJOR} ensures compatibility with both Qt5 and Qt6, and properly links the required modules. Hope this helps someone else facing the same issue!

And this links also helps:

https://doc.qt.io/qt-6/qtprintsupport-index.html