Modem/Router Fast 5688W

I have 2 USB-C external modems (500GB each) and when connected to the USB-C port on the back of the modem there is nothing in the app, or through the browser using 192.168.12.1. I've tried everything I can think of and there is also nothing in the modems owners manual giving any directions. My end goal is just to share and external drive with my home network.