You'll need an account with UPS before you can activate this carrier service on your plug&paid store.
Register for an account with UPS
If you've negotiated a discounted rate with UPS, then you can enter your UPS account number when you activate your UPS service to give you the option of displaying discounted rates to your buyers in the shopping cart.
To register for an account:
Visit the UPS website and, from the drop-down list, choose the country where your store is located.
Click Sign-up in the bar at the top of the page.
Fill in the form as required.
Accept the Terms and Conditions, then click Next.
Your registration is complete.
If you have any problems with this stage of the UPS setup, you must contact UPS directly.
Obtain your XML Access Key from the UPS Developer Resource Centre
Before you request an XML Access Key, make sure that you've already registered an account with UPS.
To request an XML key:
Log into your UPS account, then click on Customer Support in the menu bar at the top of the page.
Click Technology Support:
From the Technology Support Menu, click Developer Resource Centre:
Select UPS Developer Kit from the Developer Resource Centre Menu:
Click Request an Access Key:
If you haven't yet opened an account, you'll need to do this now:
If you had to open an account, you can now return to the UPS Developer Kit page and request the access key from Step 5.
Make a note of your XML Access Key when you receive it (the key might be sent to you in an email.)
Verify that the shipping rating you’re registering for is in Production mode.