CMake - Link library included into the project - c++

Question

I'm trying to include the GMP library into my project.
This is my folder tree:
As you can see, the gmp folder (that contains include and lib) is into the include folder.
This is my app/CMakeLists.txt:
cmake_minimum_required(VERSION 3.18)
add_executable(
${PROJECT_NAME}
../include/KMC/kmc_api/kmc_file.cpp
../include/KMC/kmc_api/kmer_api.cpp
../include/KMC/kmc_api/mmer.cpp
main.cpp
)
include_directories(
${CMAKE_SOURCE_DIR}/include
${CMAKE_SOURCE_DIR}/src
)
target_link_directories(${PROJECT_NAME} PUBLIC
${CMAKE_SOURCE_DIR}/include/gmp/lib
)
target_link_libraries(${PROJECT_NAME} PUBLIC
gmp
gmpxx
)
target_include_directories(${PROJECT_NAME} PUBLIC
${CMAKE_SOURCE_DIR}/include/gmp/include
)
target_compile_definitions(${PROJECT_NAME} PRIVATE DEBUG=1)
and this, is the CMakeLists.txt in the project root:
cmake_minimum_required(VERSION 3.18)
set(CMAKE_CXX_COMPILER "/usr/local/bin/g++")
project(MyProj)
enable_language(CXX)
set(PROJECT_VERSION_MAJOR 1)
set(PROJECT_VERSION_MINOR 1)
set(CMAKE_CXX_FLAGS "-Wall -Wextra -Wpedantic -pedantic-errors -fopenmp")
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_VERBOSE_MAKEFILE ON)
include(CMakeToolsHelpers OPTIONAL)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
include_directories(include)
include_directories(include/KMC)
add_subdirectory(app)
After, cd build && cmake .. I run make -j12 and than, -the compilation fail:
[100%] Linking CXX executable DynaDBG
cd /Users/th3g3ntl3man/Desktop/Repository/DynaDBG/build/app && /usr/local/Cellar/cmake/3.18.4/bin/cmake -E cmake_link_script CMakeFiles/DynaDBG.dir/link.txt --verbose=1
/usr/local/bin/g++ -Wall -Wextra -Wpedantic -pedantic-errors -fopenmp -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.3.sdk -Wl,-search_paths_first -Wl,-headerpad_max_install_names CMakeFiles/DynaDBG.dir/__/include/KMC/kmc_api/kmc_file.cpp.o CMakeFiles/DynaDBG.dir/__/include/KMC/kmc_api/kmer_api.cpp.o CMakeFiles/DynaDBG.dir/__/include/KMC/kmc_api/mmer.cpp.o CMakeFiles/DynaDBG.dir/main.cpp.o -o DynaDBG -L/Users/th3g3ntl3man/Desktop/Repository/DynaDBG/include/gmp/lib -Wl,-rpath,/Users/th3g3ntl3man/Desktop/Repository/DynaDBG/include/gmp/lib -lgmp -lgmpxx
Undefined symbols for architecture x86_64:
"__ZlsRSoPK12__mpz_struct", referenced from:
__ZlsIA1_12__mpz_structS1_ERSoS2_RK10__gmp_exprIT_T0_E in main.cpp.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
make[2]: *** [app/CMakeFiles/DynaDBG.dir/build.make:151: app/DynaDBG] Error 1
make[2]: Leaving directory '/Users/th3g3ntl3man/Desktop/Repository/DynaDBG/build'
make[1]: *** [CMakeFiles/Makefile2:116: app/CMakeFiles/DynaDBG.dir/all] Error 2
make[1]: Leaving directory '/Users/th3g3ntl3man/Desktop/Repository/DynaDBG/build'
make: *** [Makefile:106: all] Error 2
UPDATE:
Compiling the example I have this error: