There are several ways. If you have an AppleTV, there is a really simple solution since there is a Lightroom CC app for that and it works great. For an Android based device such as the Fire TV, you would simply use chrome cast from an Android device running Lightroom CC or from a desktop machine.
Can you navigate your TV to www.lightroom.adobe.com and sign in?
Update: I just tried it on a year old Samsung 4K. The pictures displayed, but there are limitations. The Samsung browser did not allow a slideshow nor am I sure that adjustments could be made.