code: public function api()
      {
          if (!$this->api) {
              // Get the domain and token
              $shopDomain = $this->shopify_domain;
              $token = $this->session()->getToken();
  
              // Create new API instance
              $this->api = ShopifyApp::api();
              $this->api->setSession($shopDomain, $token);
          }
  
          // Return existing instance
          return $this->api;
      }
docs: Creates or returns an instance of API for the shop.
  
  @return \OhMyBrew\BasicShopifyAPI