YouTube embed URL validation regex in Laravel 8 in controller

Question

I want to validate my youtube URL like this https://www.youtube.com/embed/xxxxxxxx. How to use the regex in variable link for this?

my code is like this in controller

$validatedData = $request->validate([
    'title' => 'required',
    'subtitle' => 'required|unique:news',
    'category' => 'required',
    'link' => 'required|regex:??',
    'image1' => 'required|image',
    'image2' => 'image',
    'image3' => 'image',
    'image4' => 'image',
    'content' => 'required'
]);