It might help if you told us the full exact text of the "need to update" message you are seeing. Also helpful would be the full model name and number of your Roku, as shown via Settings > System > About.
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.
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Ultra 4800 | Streaming Stick 4K+ 3821 | TCL Roku TV 43S245/C107X