You can find this option when you navigate to WooCommerce → Settings → General to the end of the General Options.

It’s possible to change the following settings on the settings page (General): #

  1. Disable create on order screen:
    This will disable the button to create new product serial number items inside an order. This way
    they have to be created in a shipment or on the product serial number page first.
  2. Exclude variations from search:
    By default, we search for products and variations when creating serial numbers
  3. Search for product names in Shipment screen:
    Enable this to search for product serial numbers by product name in the Shipment screen
  4. Search for product names in Order screen:
    Enable this to search for product serial numbers by product name in the Order screen
  5. Show Serialnumbers My Account:
    Show Order Serialnumbers in the frontend in each order at my account and in emails
  6. Auto Assign:
    Auto Assign available Serial Numbers to orders when they are created.
  7. Auto Unassign:
    Auto Unassign available Serial Numbers from orders when their status is failed or cancelled.
  8. Add Order Note:
    Add an order note if a serialnumber is added or removed to an order item