PayNow is only available to services using XPay by Debitsuccess.
The PayNow feature is managed through Settings > Service Settings > [Your Service] > App Settings. This menu item can be accessed by Super Admin users and Provider Level logins to Office.
To turn on PayNow, scroll down to Home, then click the toggle. When it turns orange, as per the image below, the feature is active.
Just click the toggle again to deactivate PayNow.
PayNow transactions reconcile automatically. If you want to identify the transactions paid via PayNow, you can run the Parent Transaction report under Reports > Financial Reports > Parent Transaction. PayNow transactions will show in the report as DAILY PAY NOW, visible in the Receipt Method column.