Print Multiple packages per ship - UPS
Shipping Manager - Allow multiple packages for a shipment
Example Shipping Manager UI; which has box `Number Of Labels` :
For example, admin chooses Number Of Labels = 3 , and click `Print Shipping Label`
`shipping_manager.js` calls ShippingManager/Post/Index
Behind the scenes, app/code/Frans/ShippingMethods/Model/Carrier/Ups.php function requestRestQuotes() sends multiple packages to UPS API. UPS returns with 3 labels for 3 packages
With the 3 zpls returned, js function writeToSelectedPrinter(zpls) is called. This function sends 3 zpl labels to the BrowserPrint SDK
BrowserPrint sends those 3 labels to the physical Zebra printer.


