How to get Amazon IOSS order numbers
Whether you are using Lite, Professional, Premium or Enterprise One Stop Order Processing, you will need to update the Amazon Order Reports.
You need to the ioss-number field to the Amazon Reports. To add this do the following:
1 Logon to Amazon Seller Central.
2 Select the Orders->Order Reports menu option.
3 For New Orders reports click on the Add or remove order report columns link
4 Under the Optional Columns section, at the end is a field IOSS Number.
5 Enable this field and click on Save Changes.
6 Import orders from One Stop Order Processing.
NOTE : You need to use at least version 47 of One Stop Order Processing.