Using the IOX-NFC relay function is an..unreliable/wildly unsafe method of dealing with safety-critical functions like ignition or starter inhibit. I know IOX-Keyless is a thing here in US/Canada, I'd suggest asking your PAM about options in your section of the world.

Now, onto the fun, totally unsupported, and "You can't sue me if your car burns down an orphanage" part:

Disclaimer: I've played around with this but I've never really had it work the way I wanted to or expected. The magic of the IOX-NFC black box strikes again. Btw, here's the official tooltip that tells you "it works but just don't expect it to do it right away":

"Pressing this [DriverKey] returns the Driver ID relay settings to default. The External Relay will be controlled by the Driver's ID key if Driver Identification Reminder is enabled under the Driver Feedback tab. The setting will take effect immediately if the vehicle is currently connected to the service or, otherwise, the next time it communicates."

The DriverKey option is the auto-trigger for the relay when a fob is scanned by the reader. Upon a successful read, the relay changes state. However, unless you exploit something like the DriverWhiteList (DriverApprovedList I think now?), any successful Geotab fob read will stop the Driver ID beep and click the relay on. You can force a state (On/off) or let the NFC reader handle it (DriverKey).

The Keyless beta firmware supports a continuous connection custom parameter that keeps an always-on connection back to the Geotab gateway to get commands. Maybe it works on the regular firmware version.