OpenCV + Eclipse on Linux - Build issues - c++

Question

I downloaded opencv from here and extracted it to /home/XXXX/Documents/opencv-4.4.0.
I want to link it to Eclipse. So I did this -
In the project settings -> GCC C++ Compiler -> include path I gave /home/XXXX/Documents/opencv-4.4.0.
Then in the linker section I added the libraries and set the library search path to /home/XXXX/Documents/opencv-4.4.0 and even /home/XXXX/Documents/opencv-4.4.0/include.
When I build the project, I get this error -
18:50:10 **** Incremental Build of configuration Debug for project displayImage ****
make all
Building file: ../src/displayIMage.cpp
Invoking: GCC C++ Compiler
g++ -I/home/XXXX/Documents/opencv-4.4.0 -I/home/XXXX/Documents/opencv-4.4.0/include -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/displayIMage.d" -MT"src/displayIMage.o" -o "src/displayIMage.o" "../src/displayIMage.cpp"
In file included from ../src/displayIMage.cpp:1:
/home/XXXX/Documents/opencv-4.4.0/include/opencv2/opencv.hpp:48:10: fatal error: opencv2/opencv_modules.hpp: No such file or directory
48 | #include "opencv2/opencv_modules.hpp"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [src/subdir.mk:20: src/displayIMage.o] Error 1
"make all" terminated with exit code 2. Build might be incomplete.
I followed everything according to this tutorial. I tried running pkg-config --cflags opencv to find the right paths but that gave me this error -
Package opencv was not found in the pkg-config search path.
Perhaps you should add the directory containing `opencv.pc'
to the PKG_CONFIG_PATH environment variable
No package 'opencv' found
What am I doing wrong?