staffmanager/app/Http/Requests/UpdateUserRequest.php

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Support\Facades\Auth;

class UpdateUserRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return Auth::user()->hasRole('admin');
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'email' => 'required|email',
            'name' => 'required|string',
            'uuid' => 'required|max:32|min:32',
            'roles' => 'required_without_all'
        ];
    }
}