Roku 4 is not in the current product line, but it is still being supported and can run the current Roku version 10.5 operating software.
If plugging it into power and connecting it to the tv doesn't initiate the setup process, do a Factory reset on the Roku. Find and press the reset button for a MINIMUM of 30 seconds. This will cause the Roku to restart with a cleared memory and start the setup process again.
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
The 4 is still very usable. About the only channel not supported is Apple TV+. When setting up, it may use the old version of telling you to go to a web site. If so, make sure to EXACTLY type in the FULL address!! Do NOT accept any partial suggestions from a browser or search bar! I'm not sure if it will do a firmware update before or after setup, which is why I give the warning. Newer firmware has you type in an email address that is used to send you all the info and correct links.