Linker fails with "undefined reference to Class::Class()" even when linked manually

Question

C:\Users\ologi\AppData\Local\Temp\ccq7ya3B.o:main.cpp:(.text+0x15): undefined reference to Vector<int>::Vector()
C:\Users\ologi\AppData\Local\Temp\ccq7ya3B.o:main.cpp:(.text+0x26): undefined reference to Vector<int>::append(int)
C:\Users\ologi\AppData\Local\Temp\ccq7ya3B.o:main.cpp:(.text+0x32): undefined reference to Vector<int>::print()
collect2.exe: error: ld returned 1 exit status

This is the error message that I get when compiling the files below:

main.cpp

#include "Vector.h"

int main(){

    Vector<int> a = Vector<int>();
    a.append(1);
    a.print();
}

Vector.cpp

#include "Vector.h"
#include <iostream>

template <typename T>
T* Vector<T>::operator[](int index){
    return get(index);
}

template <typename T>
T* Vector<T>::get(int index){
    if (index < size)
        return &(array[index]);
    return nullptr;
}

template <typename T>
void Vector<T>::append(T obj) {
    T* temp = new T[size+1];
    copy(array, temp, size);
    temp[size] = obj;
    array = temp;
    size++;
}

template <typename T>
void Vector<T>::copy(T* from, T* to, int from_size){
    for (int i = 0; i < from_size; ++i){
        to[i] = from[i];
    }
}

template <typename T>
void Vector<T>::print(){
    for (int i = 0; i < size; ++i){
        std::cout << "[" << i << "]: " << array[i] << '\n';
    }
}

template<typename T>
Vector<T>::Vector() {
    size = 0;
}

Vector.h

#pragma once

template<typename T>
class Vector {
private:
    T* array;
    T* get(int);
public:
    int size = 0;
    Vector();

    void append(T);
    //void insert(T, int);
    void remove(int);
    void print();
    void copy(T*, T*, int);
    T* operator[](int);
};

I have tried with multiple commands and even CMake, still without success (the error message stays the same). I unfortunately don't even know where to start.

The commands I've tested:

g++ main.cpp
g++ -Wall -o main main.cpp Vector.cpp

g++ -c Vector.cpp -o Vector.o
g++ main.cpp Vector.o

I'm not sure it's a problem with the linker now. I've removed the template type from my class to check if that was the issue and fortunetly it's not.