Setup C++ code example with sqlite3 not working

I try to setup sqlite3 extension in a basic c++ application. I know there are still threads on this site, but I have tried all suggestions for this problem. I cannot move on, nothing was the correct solution. I want to compile the class SQLConnector.cpp (see folder structure below).

I cannot compile the application without errors.

What I have already tried:

I have already installed sqlite3 at:

  C:\sqlite3\

I have downloaded sqlite-amalgamation and created a folder with the following structure:

     sqlite_test
     ├── SQLConnector.cpp
     ├── shell.c
     ├── sqlite3.c
     ├── sqlite3.h
     └── sqlite3ext.h    

I use this command to compile the code, but it does not work:

    g++ SQLConnector.cpp - l sqlite3

This is the source code of the basic code snippet:

   #include "sqlite3.h"
   #include "sqlite3ext.h" // I have tried it also without this file.
   #include <iostream>

 int main()
 {
     sqlite3 *db;
     char *strErrorMsg = 0;
     int rc;

     rc = sqlite3_open("test.db", &db);
     if (rc)
     {
         std::cout << "Can't open database " << sqlite3_errmsg(db) << 
         std::endl;
         return 1;
     }

     std::cout << "Opened database successfully!" << std::endl;

     sqlite3_close(db);

     return 0;
 }

This is the error, I got:

 SQLConnector.cpp: In Funktion »int main()«:
 sqlite3ext.h:426:40: Fehler: »sqlite3_api« wurde in diesem 
 Gültigkeitsbereich nicht definiert
  #define sqlite3_open                   sqlite3_api->open
                                    ^
 SQLConnector.cpp:20:10: Anmerkung: bei Substitution des Makros 
 »sqlite3_open«
      rc = sqlite3_open("test.db", &db);
      ^~~~~~~~~~~~
 sqlite3ext.h:426:40: Anmerkung: empfohlene Alternative: »sqlite3_log«
  #define sqlite3_open                   sqlite3_api->open
                                    ^
 SQLConnector.cpp:20:10: Anmerkung: bei Substitution des Makros 
 »sqlite3_open«
      rc = sqlite3_open("test.db", &db);

I do not know which path I should insert into the -l option. If I remove the -l option and compile sqlite3.c, then I get more than 300 errors :-D

What can I do? I do not understand how to setup the extension probably? Can someone help me and show me his setup?

I use VSCode, but I compile manually on the shell.