clang: error: linker command failed with exit code 1 (use -v to see invocation)

I am getting a linking error with my two C++ files as seen below. Compile error

It compiles up to the point of two object files then fails on linking.

Below is my code, I commented out most of main in order to isolate the issue.

I am using the boost/JSON library. The duplicates are all from the boost JSON library.

The JSONParser file is going to take in a JSON object and turn it to a C++ object but I don't think anything to do with the actual code is the issue. Just either a library or header file issue.

main.cpp

#include "JSONParser.hpp"
/*
#include <boost/beast/core.hpp>
#include <boost/beast.hpp>
#include <boost/beast/ssl.hpp>
#include <boost/asio.hpp>
#include <boost/asio/ssl.hpp>
#include <iostream>
#include <string>
#include <thread>

namespace net = boost::asio;
namespace beast = boost::beast;
using namespace boost::beast;
using namespace boost::beast::websocket;

*/

int main (void) {

  //net::io_context ioc;
  //tcp_stream sock(ioc);
  //net::ssl::context ctx(net::ssl::context::tlsv12);

}

JSONParser.hpp

#ifndef JSONPARSER_H
#define JSONPARSER_H

#define BOOST_JSON_STACK_BUFFER_SIZE 1024
#include <boost/json/src.hpp>

class candlestick{
    private:
        double openPrice;
        double closePrice;
        double priceHigh;
        double priceLow;
        double baseVolume;
        double quoteVolume;
        bool isClosed;

    public:
        candlestick (double oP, double cP, double pH, double pL, double bV, double qV, bool iC);

        void setopenPrice(double p) {
            openPrice = p;
        }
        double getopenPrice(void) {
            return openPrice;
        }
        void setclosePrice(double p) {
            closePrice = p;
        }
        double getclosePrice(void) {
            return closePrice;
        }
        void setpriceHigh(double p) {
            priceHigh = p;
        }
        double getpriceHigh(void) {
            return priceHigh;
        }
        void setpriceLow(double p) {
            priceLow = p;
        }
        double getpriceLow(void) {
            return priceLow;
        } 
        void setbaseVolume(double v) {
            baseVolume = v;
        }
        double getbaseVolume(void) {
            return baseVolume;
        }
        void setquoteVolume(double v) {
            quoteVolume = v;
        }
        double getquoteVolume(void) {
            return quoteVolume;
        } 
        void setClosed(bool c) {
            isClosed = c;
        }
        bool getClosed(void) {
            return isClosed;
        }
};

candlestick::candlestick (double oP, double cP, double pH, double pL, double bV, double qV, bool iC) {
        openPrice = oP;
        closePrice = cP;
        priceHigh = pH;
        priceLow = pL;
        baseVolume = bV;
        quoteVolume = qV;
        isClosed = iC;
};

candlestick createCandlestickObject ();

#endif

JSONParser.cpp

#include "JSONParser.hpp"
#include <iostream>
#include <sstream>
#include <string>

candlestick createCandlestickObject () {
    candlestick c (2, 2, 2, 2, 2, 2, true);

    return c;
}

By commenting out the #include "JSONParser.hpp" out of main, I was able to remove the error, therefore definitely a linking issue.