I don’t understand constructor function with object inside it

I am a Javascript novice, while doing a course, everything was going all right until I got to the “prototype chain” part of the course.
I am here to ask if someone can explain to me this exercise:

This is the exercise copied and pasted from the course:

The Shape function will take two arguments: x and y. Store these values in an object position on the instance (this).

For reference see this example. The tests will invoke Shape with the new keyword, creating an object and setting it to this within the function.

The position should have keys x and y containing the corresponding values:

const shape = new Shape(5, 10);

console.log(shape.position.x) // 5
console.log(shape.position.y) // 10

Notice that position is an object with two keys x and y!

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The example is clear, I understand it:

function Car(make, model) {
    this.make = make;
    this.model = model;
}

const car = new Car('Toyota', 'Camry');
const car2 = new Car('Honda', 'Civic');

console.log(car.make) // Toyota
console.log(car2.model) // Civic

But the exercise wants me to store x , y in the object position in the function Shape:

My solution (wrong):

function Shape(x, y) {
    // store x and y in this.position
    const position = {
        this.x = x
        this.y = y
    }


}

the original exercise:

// Our Shape "Constructor"
function Shape(x, y) {
    // store x and y in this.position
}

module.exports = Shape;

Can someone explain to me what is wrong with my code? I know I can peek and see the correct solution to this exercise, but since I don’t understand it, I feel that I can’t move forwards.
Thank you for your help.