MyCashier.php

<?php

namespace App\Billing;

use Laravel\Cashier\Cashier as LaravelCashier;

class Cashier extends LaravelCashier
{
  /**
   * The current currency.
   *
   * @var string
   */
  protected static $currency = 'eur';
  
  /**
   * The current currency symbol.
   *
   * @var string
   */
  protected static $currencySymbol = '€';
  
  /**
   * The custom currency formatter.
   *
   * @var callable
   */
  protected static $formatCurrencyUsing = 'customCurrencyFormat';
  
  /**
   * The custom currency formatter.
   *
   * @param int $amount
   */
  protected static function customCurrencyFormat($amount)
  {
    // return your custom format here
  }
}