The CATEGORY MAPPING page lists all the fetched reverb categories. Admin has to select the categories to which the products need to be assigned.

To select the required categories for mapping

1. Go to the WooCommerce Admin panel.
2. On the left navigation bar, click the RAKUTEN menu.
3. In the left panel, click the CATEGORY MAPPING tab.
   
4. After clicking the page will appear as shown in the image:
   
5. Under Root Categories, click the required category.
   Next level categories list appears. Click the required category.
   Note: Keep clicking every next level required categories until the last level categories list and the corresponding checkboxes appear as shown in the following image:
   
6. After selecting all the levels of categories your categories will automatically save successfully and you will get a message that categories saved successfully.