Issues with validation of signup form

I'm adding a validation to my sign up form , the validate code is working but the errors don't shows up in the page

PHP code

$this->validate($request, [
            'email'=> 'required|email|unique:users',
            'first_name'=> 'required|max:120',
            'password' => 'required|min:4'
            ]);

Welcome.blade.php code

@section('content')
@if(count($errors) > 0)
<div class="row">
    <div class="col-md-6">
        <ul>
            @foreach($errors->all() as $error)
                <li></li>
                @endforeach
        </ul>
    </div>
</div>
@endif

the php code is working because if i tried to register with an email that already taken it wont register but the error is that errors are not showing up in the welcome page

via Chebli Mohamed