Collecting Sales From Shopify
To collect from Shopify, you need to create API credentials in your admin, then add them to the credentials dialog in Packing Partner.
Enabling Shopify
You also need to enable the Shopify feature under Collect Sales and Update Sales from Tools>Features
Adding Shopify credentials
Click Apps on the bottom left corner, then click Private Apps/Generate API credentials

Marking sales despatched
To mark sales despatched, under permissions, you must set Orders, Transactions and Fulfilments to Read/Write
Enter the details shown above, for Packing Partner and click Save.

Copy the two fields API Key and Password into Tools>Credentials>Shopify API
to copy
click and drag the mouse across the numbers for the API key and password

See Also
Supported Channels - Supported Carriers