Check these settings if MPL shipments or labels don't work as expected. For the basic setup, see Enabling direct integration for MPL.
The shipment is created in Delivery Gateway, but MPL doesn't see it
In the Delivery Gateway admin, under MPL provider settings, turn on Automatically generate waybill for shipment. Without it, the shipment shows as Waiting for collection in Delivery Gateway but doesn't reach the MPL system. Create a new shipment after changing the setting.
Cash on delivery orders fail
Enter your bank account number under Merchant settings / CashOnDelivery in the Delivery Gateway admin. MPL returns an error for cash on delivery shipments without it.
The label can't be created because of the accounting code
Copy the accounting code exactly as MPL gave it, including any leading zeros.
"Reference ID already exists" error
When you create a shipment again for the same order, change the Reference ID in section 1, which belongs to the shipment. The Reference ID in section 4 belongs to the parcel; changing only that one doesn't help. One shipment can contain several parcels, for example when the products don't fit in one box.
If the problem remains, contact us in the chat with your store URL and the order number.