in literal desperate need of help adjusting brightness and/or menu/input from phone or via remote

please i am in desperate need of assistance, can someone guide me through how to adjust my roku express' brightness via phone or the remote as opposed to me having to get up and click the input, menu, and channel buttons when trying to fall asleep with something on. please someone walk me through this step by step, more information; idk if it is relevant or helpful, i have an element branded TV, and a roku express (hdmi port), and i have developer mode enabled and slightly familiar with third-party apps