4Seller support authorize UPS, which can help seller fulfill orders easily and conveniently.
Step 1: Register a UPS account at: https://developer.ups.com/get-started?loc=en_US
Step 2: Enter UPS API page, copy Client ID,Client Secret, Billing Account Number.

Step Three: Click settings-Order&Shipping-Shipping Carriers-Major Parcel Carriers-Select UPS and add account.

Step 4:Fill the infoamtion and click connect.

If you have any further questions or suggestions, please do not hesitate to contact our support team.