Maintenance for the week of August 3:
• [COMPLETE] ESO Store and Account System for maintenance – August 4, 5:00AM EDT (9:00 UTC) - 4:00PM EDT (20:00 UTC)
I used the Support Knowledge Base search and found this:
In order to set up a recurring ESO Plus membership via PayPal, you will need to verify your PayPal account through a bank account or with credit card first. If you are unable to use a credit card to verify your PayPal account, please contact PayPal support for further assistance.