By adding a tracking number to a sale, plug&paid will assign that number to the purchase and inform the buyer via email. This option is available for all your sales with shipping.
You can add a tracking number to a sale in two main ways:
1. In your Pending Orders or in your Invoices page click the 3 dots menu on the right and select the "Add Tracking" option.
2. In the info sheet of your sale click the 3 dots menu on the top right and choose the "Add Tracking" option.
Note: If shipping carrier (UPS, Fedex, DHL) credentials are added to your account, then the option will be unavailable as plug&paid will receive tracking numbers directly from the carrier.