I don’t understand the concept of association in C++

This is my code examples:

Association: Object A knows about object B. Class A depends

from B but does NOT consist of it

Car 
{
    ???
};

Agregation don’t manages life cycle

Car
{
    Engine* engine;
    
    Car(Engine& eng) {
        engine = eng;
    }
};

Composition manages life cycle

Car 
{
    Engine* engine;
    
    Car() {
        engine = new Engine();
    }
    
    ~Car() {
        delete engine;
        engine = nullptr;
    }
};

I saw such an example

Car 
{
    Engine* engine;
};

but I believe that this is not an association because it violates the principle Class A depends

from B but does NOT consist of it