bug when using slug in route

i have Product Model with this function

public function getRouteKeyName()
{
  return 'slug';
}

public function getRouteKeyName()
{
  return 'slug';
}

public function getRouteKeyName()
{
  return 'slug';
}

public function getRouteKeyName()
{
  return 'slug';
}

and when try edit page i got 404 error