Once the Configuration is completed and saved, OnBuy categories will appear in the admin panel in the Categories section.

To see all the categories,

1. Place the cursor on CO on the left navigation bar of the admin panel as shown below:
2. Now Click on Categories.
3. On clicking Categories, you will be navigated to a page as shown below:
   
4. To Fetch new Categories Click on Fetch Category Button on the top right corner.
   
5. Now, you can see all the OnBuy categories.
6. By doing so all the categories will get fetched from the OnBuy marketplace to your Opencart store.