Hi Lawrence, good timing! I’ve just answered your query via Premium Support. I will paste my response here for posterity (I’ve also added it to the Usage document to help others; https://www.visser.com.au/documentation/store-exporter-deluxe/usage/).
The custom Post meta key where the PayPal Transaction ID is saved is called: _transaction_id
1. Open the WooCommerce > Store Export > Quick Export screen and select the Orders export type
2. Enter ‘_transaction_id’ into a new line within the Order meta textbox under Custom Order Fields
3. Click Save Custom Fields
4. Check the new Transaction ID Order export field to include it in your export
That’s it. If you need additional support feel free to respond to your existing ticket or open a new one via the Support page 🙂