Hello, I compiled OpenCV from its source for using with Qt and Qt Creator. Everything is set up. You can simply download the repo and unzip into C:\ drive then unpack the 7z archive in the doc folder and move this folder and .qch file to Qt Docs (example: C:\Qt\Qt5.13.0\Docs\Qt-5.13.0) folder inside your Qt installation folder. Thats it!
After the installation completed then open your project file (.pro file) and add this line below:
include(C:/opencv/opencv410.pri)
And Ctrl+S to save this project then its done.
After the installation completed then open the opencv410.pri file and find unix section then change the INCLUDEPATH and LIBS path to you extracted path for example (/home/your_username/opencv/include and /home/your_username/opencv/x64/unix_gcc/lib) then save .pri file. After this step open your project file (.pro file) and add this line below:
include(/home/your_username/opencv/opencv410.pri)
And Ctrl+S to save this project then its done.