Use Magento 2 integration and create shipping labels.
Tracking information is automatically sent to Magento after creating a shipping label.
1. Create integration key
Go to Magento 2 Admin -> System -> Extensions -> Integrations
Click "Add new Integration"
In "Name" field enter "MultiParcels"
Switch to "API" tab and give permissions to Sales->Operations->Orders->Actions->View and Ship
Click "Save & Activate"
Agree to give permissions
Copy the "Access Token"
2. Add integration in MultiParcels Platform
Go to Shops and click "Add" near Magento 2
Enter the address of your Magento 2 shop and the key you generated in Magento 2 Admin