What plan are the devices on right now? If I recall correctly, there is an automatic change from Pro to ProPlus if you plug in one of these IOX devices. There is nothing to manually do from the client or reseller if the devices are on Pro. Same if you enable Active Tracking, the device will automatically transition from Pro to ProPlus.
If the devices are on Regulatory or Base, there is no automatic migration. You need to change the devices onto the Pro or ProPlus plan first to enable these functionalities. In order to do that, you typically need to contact your reseller. Plan changes cannot be made through the Geotab API. There is a distinct API for resellers to automate this, but it couldn't be done in the Geotab API runner.