The usual way to use a compiled VTK library through CMake is to use the CMake variable -DVTK_DIR:PATH=/install/folder/lib/cmake/vtk-9.3 which contains the vtk-config.cmake file.
I’m not familiar with OCCT build system, but it looks like it uses CMake with the classic find_package(VTK ...) command. So the above method should work.
Let us know if it helps.
Best,
François