To set up your return shipping address, go to ‘Account’ in the left-hand navigation, then go to the ‘Shipping and Sales Tax’ tab. Here, enter your relevant return shipping address and click save. Please note that we cannot accept PO Boxes as the ‘ship from’ address because a physical address is needed for all supported shipping carriers.
It is likely that your ship from and return shipping addresses are the same. In that case, there is a checkbox on the shipping settings page making them identical.