Sixfab sim with router for fallback

I got a sixfab sim with the intention of using it for fallback for my ASUS RT-AC86u. I got it with a Exvist 4gd usb dongle and a Sierra Wireless module MC7700 4g LTE. I was under the impression this all should work with Linux and the router runs Linux, the Merlin firmware. So far I’m testing on a windows system and it recognized the drivers for the dongle and the wireless card but I don’t see it as a network device yet. I registered the sim and want to test it before I load it with money. I do have a Pi 4 and will try the it and the router to see if the dongle and wireless card work.