Unable to integrate OpenFHE to my project

I’m new to the OpenFHE. Trying to install on ubuntu 20. Installation is successful. Followed all the instructions in the Building User Applications — OpenFHE documentation (openfhe-development.readthedocs.io)
but the make is not happening.
error is :

[ 50%] Building CXX object CMakeFiles/openfhe_experiment.dir/demo-simple-example.cpp.o
c++: error: unrecognized command line option ‘-fopenmp=libomp’; did you mean ‘-fopenmp-simd’?
c++: error: unrecognized command line option ‘-fopenmp=libomp’; did you mean ‘-fopenmp-simd’?
make[2]: *** [CMakeFiles/openfhe_experiment.dir/build.make:63: CMakeFiles/openfhe_experiment.dir/demo-simple-example.cpp.o] ror 1
make[1]: *** [CMakeFiles/Makefile2:76: CMakeFiles/openfhe_experiment.dir/all] Error 2
make: *** [Makefile:84: all] Error 2

  1. Do the examples in the OpenFHE folder work? If not, please list out the exact commands you used to install the library. This can help us recreate the issue you ran into. If yes, proceed to step 2.

  2. List out all the commands and include a link to your code

Could it be what is in this issue unrecognized command line option ‘-fopenmp=libomp’ [solved (kind-of)] - FreeCAD Forum
check to make sure you are using the g++ compiler? report back with the version you are using. (simply enter
g++ -v
)

the version of g++ is 9.4.0

Please post your exact commands