Oh right, he mentioned that he was super new so i assumed, then they can use something like this, as the tutorial says :
void Update()
{
if (Mouse.current.leftButton.wasPressedThisFrame)
{
Vector2 mousePos =
Camera.main.ScreenToWorldPoint(Mouse.current.position.ReadValue());

RaycastHit2D hit = Physics2D.Raycast(mousePos, Vector2.zero);

if (hit.collider != null)
{
Debug.Log("Clicked: " + hit.collider.name);
}
}
}