Hi JSC ,
First of all, thanks a lot for using our plugins!!!
The data you want is in the Products entity, unfortunately, we didn't add this entity as an Inventory Logs' subentity. This is because we wanted to keep the exports as simple as possible, and, in this case, the relation between the ATUM order items and the Product entity may vary depending on if you're using simple or variable products. For the first ones, the product_id field must be used for the relation, and for the second ones, it will also depend on if you want the variable product info or the variations info (here, the variation_id field must be used).
As you say you have limited knowledge, the easiest way to get the info you need is to use an Inventory Logs export and a Product export. After that, you can use spreadsheet software to relate both exports by the field you need (product_id and/or variation_id).
There's another way to get your export working, but you'll need some coding knowledge, as you will need a pair of the ATUM export hooks to add the Products entity as an ATUM Order Items subentity.
Specifically, the following hooks:
1. atum/export/known/inventory_logs/subentities in wp-content/plugins/atum-export-pro/classes/KnownEntities/Entities/InventoryLogs.php
2. atum/export/known/atum_order_items/subentities in wp-content/plugins/atum-export-pro/classes/KnownEntities/Entities/AtumOrderItems.php
Hope this helps and sorry for any inconvenience caused,
José Andrés