InvoiceShelf/app/Http/Requests/DeleteUserRequest.php

<?php

namespace InvoiceShelf\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Validation\Rule;

class DeleteUserRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'users' => [
                'required',
            ],
            'users.*' => [
                'required',
                Rule::exists('users', 'id'),
            ],
        ];
    }
}