I just connected 245GB to my ONN device yesterday. Your screen looks very similar to the ONN. It would be a big help if you said what device you are using. Cube, stick, ONN etc
For mine I had to follow Troypoints guide to enter developer mode, install a terminal and enter some commands
What device are you using?
Check the usb drive format. I think androidTV can only use one of them- exfat, ntfs, etc. I think if it's <the wrong> format it can read the disk but can't use it.
I have a Sony a90j with a T7 SSD from Samsung, it says that exact same thing too but if I go to the devices storage I can see it has apps installed, other files, and files from apps like kodi. Maybe the wording just weird/bugged out?
Do you see mount button? Use paragon app, total commander
Try going to developer options. Look for an option that says something like "Allow apps to be written to external storage, regardless of manifest values" that might do something
Do you need to format it?