Redirect to external website in Laravel without adding http(s)://

My web app needs to redirect user to an external website using

redirect()->away($url). 

However, this won't work if url does not contain "http://" or "https://". Because the url is user defined, I don't think it's a good way to manually add "http://" or "https://". Is there any way in Laravel that can be used to redirect user to external website without need to add "http(s)://"?

via Chebli Mohamed