You can easily deactivate One TouchTM by turning it off within your PayPal account. Just log in at www.paypal.co.uk and go to your Profile, click the Security tab, and then edit the “Stay Logged in for Faster Purchases” option. Business account users can deactivate One TouchTM by clicking the Profile icon and selecting “Log out of all devices” from the drop down menu.
Other alternative methods to deactivate /revoke One Touch
Call PayPal Customer Service
On changing your password, PayPal automatically revokes consent
PayPal can force ‘Show Login’ for suspicious activity or if a transaction bears higher risk
You can turn it off in your PayPal account settings