To view failed orders,

The section for “failed orders” includes all orders that were not successfully retrieved from the Magento 2 store. There may be various reasons why a product cannot be properly retrieved from the store, such as the product being out of stock, or having a missing SKU.

1. Go to the Magento Admin Panel.
2. On the left navigation bar, click on the ManoMano Integration menu.
   The menu appears as shown below:
   
3. Click on Failed Imported Orders.
   The Failed Orders page appears as shown below:
   
4. This page displays the failed orders with the order id and the reason for the failure.
5. To delete the failed orders, click on the Delete Failed Order Log button.
   The failed orders will be deleted.