How to set up dynamic email templates with Laravel and ensure fallbacks?

composer require spatie/laravel-database-mail-templates
php artisan vendor:publish --provider="Spatie\MailTemplates\MailTemplatesServiceProvider"
php artisan migrate

class UserWelcomeMail extends Mailable {
    public $data;
    
    public function __construct($data) {
        $this->data = $data;
    }
    
    public function envelope() {
        return new Envelope(
            subject: 'Welcome!',
            using: 'welcome' // DB template slug
        );
    }
    
    public function content() {
        return new DatabaseView(['data' => $this->data]); // With fallback
    }
}

Mail::to($user)->send(new UserWelcomeMail([
    'name' => $user->name,
    'url' => route('verify', $user)
]));
// Template in DB: <h1>Hi {{ $data['name'] }}!</h1>