fatal error: 'curlpp/cURLpp.hpp' file not found

I have downloaded on macOs, In Clion I copied the example they Have like this:

// Edit : rewritten for cURLpp 0.7.3 // Note : namespace changed, was cURLpp in 0.7.2 ...

#include <curlpp/cURLpp.hpp>
#include <curlpp/Options.hpp>


int main() {

// RAII cleanup

    curlpp::Cleanup myCleanup;

// Send request and get a result.
// Here I use a shortcut to get it in a string stream ...

    std::ostringstream os;
    os << curlpp::options::Url(std::string("http://www.wikipedia.org"));

    string asAskedInQuestion = os.str();
    return 0;
}

But I'm getting fatal error, what should I do? I have already downloaded the packaged and it's already unzipped in the downloads folder.