UPS - General Settings
You can go to UPS settings from the Flexible Shipping's configuration screen:
However, you can always go there directly from WooCommerce → Settings → Shipping → UPS:
Once you get there, you need to provide your credentials.
If you don't have UPS account and/or UPS Access Key, use this guide(s):
Once you finish the configuration and click Save on the bottom of this screen, API Status will change.
If you configure this integration for the first time, just don't bother about API Status for now. Just proceed with the configuration.
Next step you need to complete is to provide your address:
Now, you can change label format if you need.
Finally, some extra options.
Parcel tracking adds the tracking link to confirmation emails. These are the ones WooCommerce sends when a customer makes an order.
Shipment settings let you automate your shipping process. You can configure automatical shipments creation. Learn more about automating the shipping →
Use Weight/Dimension units to set units for your shipping. It has to be in order with units used in your origin country. Otherwise, you'll get an error while creating a shipment.
Click Save changes and you're ready to add a shipping method.