Could you use the Tracker One? It’s a Tracker SoM inside an enclosure, and the ONE523 is available now.
If you need the Tracker SoM, the T524 should be available late April or early May 2023 (not 52 weeks).
You cannot use a 3rd-party SIM with any Tracker SoM or Tracker One device.
The recommended way to access an external service is to use the Particle cloud to transmit the data to a webhook, which can export data to an external service. In the case of Firebase, you can also use the Google Cloud Platform integration.
The North America versions will definitely not work in Rwanda.
One suggestion though @Dan-Kouba when you use terms like T524 and SKU it takes a while to understand for someone not familiar with the terms. I figured it out by searching ‘T524’ on the particle.io main website that it is another Tracker SoM LTE CAT1/3G/2G (Europe, EtherSIM).