Custom Card in Laravel Nova - Service Provider 1

NovaServiceProvider.php

<?php

// ...

public function boot()
{
  parent::boot();

  // Let Nova know where your compiled assets will be.
  Nova::serving(function (ServingNova $event) {
    // Only add the following line if you don't use Single File 
    // Components and plan to compile CSS separately.
    // Nova::style('nova', public_path('assets/css/nova.css'));
    Nova::script('nova', public_path('assets/js/nova.js'));
  });
}

// ...