Using laravel's HTTP tests

CustomerTest.php

<?php

namespace Tests\Feature;

use Illuminate\Foundation\Testing\RefreshDatabase;
use Illuminate\Foundation\Testing\WithFaker;
use Tests\TestCase;

class CustomerTest extends TestCase
{
    /**
     * A basic feature test example.
     *
     * @return void
     */
    public function test_example()
    {
        // $response = $this->get('/customer');
        $response = $this->withHeaders([
            'X-Header' => 'Value',
        ])->post('/customer', ['name' => 'sd','email' => '[email protected]']);
        $response->assertStatus(201);
    }
}

template.blade.php

@component('mail::message')
{{__('Mail Sent')}}
Thanks,<br>
{{ config('app.name') }}
@endcomponent

WelcomeNewCustomer.php

<?php

namespace App\Mail;

use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Mail\Mailable;
use Illuminate\Queue\SerializesModels;

class WelcomeNewCustomer extends Mailable
{
    use Queueable, SerializesModels;

    /**
     * Create a new message instance.
     *
     * @return void
     */
    public function __construct()
    {
        //
    }

    /**
     * Build the message.
     *
     * @return $this
     */
    public function build()
    {
        return $this->from('[email protected]', 'Customer')
                ->markdown('emails.template');
    }
}