See my other replay
If you set it to ship the entire order in one package, you dont need to provide package dimensions until you run the checkout wizard.In the checkout wizard, you will be able to specify UPS as your shipping provider, and set the package dimensions to use.

See my other reply under the thread:
USPS Shipping
I am also running this First Data connection in a trial mode, so I don't know if that will interfere with the shipping checkout?


