Hardware specs

I was looking for a gps tracking hardware solution with reporting range extended by Flexiroam coverage. I am not familiar with Flexiroam hardware requirements btw, whether the Flexiroam network roaming network selection ability is part of the app / hardware or part of the sim or all embedded in the cloud / Flexiroam iot function or ??
One of the tracker devices found has this in the description :-

: Our GPS trackers have an integrated SIM card that is charged via the web application and the traffic fee is only 4.90 € including VAT per activated month. The traffic fee includes unlimited tracking in Europe (EU, Norway & Switzerland) on all operators' networks.Our GPS trackers have an integrated SIM card that is charged via the web application and the traffic fee is only 4.90 € including VAT per activated month. The traffic fee includes unlimited tracking in Europe (EU, Norway & Switzerland) on all operators' networks. :

This would appear to be a similar roaming type arrangement as Flexiroam except Europe only, I’m looking for Flexiroam coverage.
The question is this, is there anything about the hardware in a tracker that is required to support the Flexiroam functionality or so long as it has a sim card tray Flexiroam sim will send and receive without a GUI or Flexiroam app installed, tracker has no screen or keys and is set up / instructed via iot remote mobile app or trackers web app or by sms from mobile phone.

Just as an example of another basic and readily available unlocked SIM card tracker device TK-419 Gps 4G LTE tracker is representative.