Review on SanDisk Ultra SDSQUNS-128G-GN6MN 128GB 80MB/s UHS-I Class 10 microSDXC Card - High Capacity Storage with Lightning-Fast Speeds by George Johnson

I bought this to add extra internal storage to my Fire HD 10 (latest model). When I tried to format it on my Fire tablet, the screen went black and there were none of the on-screen prompts you usually get when formatting (see YouTube tutorials for example). I tried to get help from Revain customer service as the SD card is 128GB and my tablet still says I only have 26GB. . They said the tablet will use the SD cards when needed, so I assume I'll use up the tablet's 26GB by then. However, I still don't understand why my settings doesn't show 128GB where it says SD card. From a YouTube video with the same tablet, mine doesn't show an SD card inserted. So I'm not sure what's wrong and I'm frustrated that nobody can help.