Hi @Bilal-Hussain
I also encourage you to review our Hardware Expansion Guide.
https://docs.modalai.com/expansion-design-guide/#usb-expansion-over-j3--j5
In there you'll see how we achieve most of our expansion is by USB. So, depending on how much current your target device needs, we can power it directly, or if you need more than the posted VBUS ICC limits for the various plug-in boards, then you can just plan on providing an external power source as well.
Once you further refine your modem/radio of choice, please keep those in mind. It may make your final integration steps much easier to know this info.
Hope this helps!!