MilesWeb does not have access to your PayPal account. You have to cancel the subscription manually from your PayPal account. Follow the below steps to cancel the PayPal subscription:
Login to your PayPal Account
Click on “Profile” then click on “Profile and Settings”
Click on “Financial information“, Check “My pre-approved payments”
Click on update
You will see a list of pre-approved payments and merchant details.
Search “MilesWeb” in merchant column.
Open the subscription and click on cancel.
This will stop the auto-payment.