I have used my Logitech MK850 KB&M set which are both Unifying compatible on a TV before and got it to work, but you really need the Unifying dongle in order for this to be possible.

In order for it to work on the TV, you'll have to pair your mouse with the Unifying dongle that comes together with it on a PC/Laptop or tablet first. Once it works fine, make sure you install Logitech Options on any of the latter devices so that the software can detect your mouse. Once that's done, only then you connect it to the USB port of your TV and it will work in an instant.

Glad to hear that it works.

As for Logitech Options, no, it's optional. Pairing with the dongle on a laptop/PC or tablet will work just fine.