How to correctly define and link a C++ class destructor to a main file?

This is a particularized question from mingw32/bin/ld.exe ... undefined reference to [class] ... collect2.exe: error: ld returned 1 exit status

There is a user-defined class inside MyClass.hpp:

class MyClass
{
    public:
        MyClass(const string& className); 

        ~MyClass() {cout << "Destructor definition instead of g++ default one?";} ; 
        ...

and you try to construct an object out of it in the main file:

#include "MyClass.hpp" //in the same directory
...
int main()
{
...
MyClass myClassObj = MyClass(myName); //here is the linker problem
...
return 0;
}

The error:

c:/mingw/bin/../lib/gcc/mingw32/8.2.0/../../../../mingw32/bin/ld.exe: C:\Users\....:Main.cpp:(.text+0x124c): undefined reference to `MyClass::~MyClass()'
collect2.exe: error: ld returned 1 exit status

There are two questions: 1. How can I build a Makefile or which g++ command can I use to have the correct linkage of MyClass into Main? 2. How can g++ use this own default destructor (in this case I did not defined it at all, still not working). Or, if I need to define one myself, how is the best way to do it?

simple compilation command:

g++ -o MyProgram.exe Main.cpp -Wall

I also tried the Makefile from : mingw32/bin/ld.exe ... undefined reference to [class] ... collect2.exe: error: ld returned 1 exit status

And I checked the toolchain dependencies by following : Makefile: How to correctly include header file and its directory?