Using KF5 with CMake - c++

Question

I'm trying to use the KPlotting widget with a Qt (v5.14) project that uses CMake (v3.10.2).
I installed the KDE Extra CMake Modules by cloning the repo, then running: cmake, make, sudo make install.
I added find_package(KF5Plotting) to my top-level CMakeLists.txt file, and target_link_libraries(${PROJECT_NAME} KF5::Plotting) in the CMakeLists.txt file in my src directory. However, when I compile I get the following error:
ui_mainwindow.h:30:10: fatal error: kplotwidget.h: No such file or directory
#include <kplotwidget.h>
This seems to indicate that the call to find_package didn't work, but I'm unsure how to check. Am I simply missing an include directory directive in CMake? Any help on how to get this to compile would be greatly appreciated!
UPDATE:
If I add REQUIRED to find_package, nothing seems to change, and the output is simply:
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found PkgConfig: /usr/bin/pkg-config (found version "0.29.1")
-- Checking for module 'portaudio-2.0'
-- Found portaudio-2.0, version 19
-- Found hamlib library at: /usr/local/lib/libhamlib.so
-- Found hamlib static library at: /usr/local/lib/libhamlib.a
-- Found hamlib static modules:
-- Found hamlib include directory at: /usr/local/include
-- Found sox library: /usr/lib/x86_64-linux-gnu/libsox.so
-- Found sox headers: /usr/include
-- Boost version: 1.65.1
-- Found the following Boost libraries:
-- system
-- filesystem
-- Found FFTW: /usr/include found components: FLOAT_LIB
boost lib: /usr/lib/x86_64-linux-gnu/libboost_system.so;/usr/lib/x86_64-linux-gnu/libboost_filesystem.so
boost inc:/usr/include
fftw lib: /usr/lib/x86_64-linux-gnu/libfftw3.so;/usr/lib/x86_64-linux-gnu/libfftw3f.so;/usr/lib/x86_64-linux-gnu/libfftw3l.so;/usr/lib/x86_64-linux-gnu/libfftw3_threads.so;/usr/lib/x86_64-linux-gnu/libfftw3f_threads.so;/usr/lib/x86_64-linux-gnu/libfftw3l_threads.so;/usr/lib/x86_64-linux-gnu/libfftw3_omp.so;/usr/lib/x86_64-linux-gnu/libfftw3f_omp.so;/usr/lib/x86_64-linux-gnu/libfftw3l_omp.so
-- Configuring done
-- Generating done
-- Build files have been written to: /home/wspeirs/src/sdhr/build
The top-level CMakeLists.txt file can be found here: https://gist.github.com/wspeirs/1948869bf7fdb6f943c143b2a223fa54
Also, I installed KPlotting via apt (libkf5plotting-dev & libkf5plotting5) on Ubuntu 18.04