@AzulBal05-
Roku menu path Settings/System/About will show you your Roku model and model number. It's a good idea to report these when asking questions because different models have different features and capabilities. If we know the model you can get better targeted suggestions.
If your Roku model us a non-4K Express model, or other model that comes with a remote without a microphone button, your remote is a basic infrared (IR) remote that controls the Roku only, and has no capability for controlling TV functions like volume. You'll have to use your TV remote for controlling TV functions,
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.".
Ultra 4800 | Streaming Stick 4K+ 3821 | TCL Roku TV 43S245/C107X