Upgrading from older PayPal integrations such as PayPal Standard or PayPal Checkout is straightforward. Simply install the PayPal Commerce extension found at https://www.cubecart.com/extensions/plugins/paypal-commerce by following the instructions in the Documentation tab. Once connected your old PayPal integrations should be disabled automatically.
To check please login to the back office of your store and got to Manage Extensions. From here please ensure that the checkbox next to each of the old PayPal extensions is unchecked. Amend and save if necessary.