How to correct __imp errors?

Question

I found on github an HTTP/HTTPS library header (https://github.com/yhirose/cpp-httplib), which says it is only necessary to import it into the archive and use it.

I created the code:

#include <iostream>
#include "httplib.h"
#include <Windows.h>

using namespace std;

int main(void)
{
  using namespace httplib;

  httplib::Client cli("http://127.0.0.1:5000");
  cli.Post("/Teste", "variavel=CPPTESTE", "application/x-www-form-urlencoded");

}

But when I compile there are dozens of errors, such as:

C:\Httplibteste\TesteHttpLib\httplib.h|1930|undefined reference to __imp_shutdown
C:\Httplibteste\TesteHttpLib\httplib.h|2020|undefined reference to __imp_ioctlsocket
C:\Httplibteste\TesteHttpLib\httplib.h|2107|undefined reference to __imp_connect

among others. I saw an article that said it was necessary to import libs such as libwsock32.a and libws2_32.a in Linker, but still the error occurs. How can I fix it?