There is an option at the bottom of the label page to select to pay from your pending funds or from PayPal.
You can change it there before you pay for the label.
You can also go into your PayPal account and disable or turn off "eBay Inc shipping" so that your PP account can no longer be used for labels.
click Settings (the gear icon by the bell) > click Payments > Manage Automatic Payments > click "eBay Inc Shipping" in the left column > Status change from "Active" to "Cancel" > it will change to "Inactive"
