The GPD doesn't seem to fully support the 7120, it is not listed in the models section.
If I hook the GPD up to ours it goes to a generic Work Center Color mode and looks just like yours where it does not show the printer on the right side or report the toner and paper levels
If it did support the printer fully it would look like this and have the secure print option in the Job type dropdown.
I would think the GPD team may have dropped the printer due to age, but that is a guess, of course the 7120 shows up as supported on the GPD page, but has the caveat that it any device may not be "Fully supported"
I'd just go ahead and replace the global driver with the native driver for the printer.
We have a Xerox WorkCentre 7120 printer.
We are looking to use the "Secure Print" capability.
Problem
The driver properties do not show the option to 'Secure Print'.
The only option it shows in the printer properties > printing options tab > job type drop down triangle is "normal print".
We are using the latest driver "GPD PCL6 V3.7.469.9.0"
I have installed the print driver locally and have attached an image.
Thank you for looking at this.