Cannot use gmp and mpfr

I am trying to compile the following code from CGAL website: https://doc.cgal.org/latest/Triangulation_2/Triangulation_2_2for_loop_2_8cpp-example.html

It compiles perfectly from commandline in Mac 10.15.7. I am simply using g++ -std=c++17 -lgmp -lmpfr main.cpp. The I can run the program using ./a.out

But it is not working from Clion. I am using the following in CMake options under Preferences:
-DCMAKE_CXX_FLAGS="-O3 -Wall -Wextra -I/usr/local/include".
If I include -lgmp and lmpfr, looks like they are not recognized.

Any help will be appreciated.