izyim/database/factories/PackingListFactory.php

<?php

use Faker\Generator as Faker;

$factory->define(App\Models\PackingList::class, function (Faker $faker) {
    return [
        'order_id' => $faker->numberBetween(1, 300),
        'reference_no' => $faker->numberBetween(1000000, 9999999),
        'confirmed' => 1,
        'created_at' => $faker->dateTimeBetween($startDate = '-30 days', $endDate = '30 days'),
        'updated_at' => $faker->dateTimeBetween($startDate = '-30 days', $endDate = '30 days')
    ];
});