code: public function shop(string $shopDomain = null)
      {
          $shopifyDomain = $shopDomain ? $this->sanitizeShopDomain($shopDomain) : (new ShopSession())->getDomain();
          if (!$this->shop && $shopifyDomain) {
              // Grab shop from database here
              $shopModel = Config::get('shopify-app.shop_model');
              $shop = $shopModel::withTrashed()->firstOrCreate(['shopify_domain' => $shopifyDomain]);
  
              // Update shop instance
              $this->shop = $shop;
          }
  
          return $this->shop;
      }
docs: Gets/sets the current shop.
  
  @param string|null $shopDomain
  
  @return \OhMyBrew\ShopifyApp\Models\Shop