"Roku TV" is one that has Roku functionality built in and does not need an external Roku streaming device to be connected to it.
Roku TVs are available from several manufacturers but as far as I know Samsung is not one of them. Samsung smart TVs may have a Roku Channel app installed but this just gives access to Roku's own The Roku Channel and does not provide full Roku capability.
If you are using a separate Roku device connected to your Samsung what is the Roku model and model number? You can determine this by going to Settings-System-About from the Roku home screen.
Roku Community Streaming Expert I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well. If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X