Thanks for reporting back. It may help the next person that has a similar problem.
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
It must be an old model, when the Olevia was first released the models were made by RCA, LG, Philips, or Yamaha. Then around 2010 they released models that used a code NO other brand ever used, it was about a two years before oem & universal remotes were released with this new code.
No other tv brand used the newer Olevia code, so without Olevia listed there another brand to try. Sorry. If your Olevia tv has CEC feature, you might be able to switch your Roku remote from TV IR to Roku CEC? Watch for PM.
Edmund Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution." If you appreciate my answer, maybe give me a Kudo.