Method one:
Kindly note that your can delete your paypal account via My Alibaba - Transactions - Bank/Card Accounts. Please understand that this operation can only be done via PC.
Method two:
You can also unbind PayPal account in the PayPal backend. Here are the steps to cancel automatic payments in the PayPal backend:
Step1.Log in to your PayPal account.
Step2.Click on the "Settings" icon on the top right corner.
Step3.Click on "Payments" and then "Manage pre-approved payments".
Step4.Select the merchant or subscription you want to cancel.
Step5.Click on "Cancel" and then "Yes" to confirm the cancellation.
Your automatic payments will now be cancelled.