Cannot press Channel Up/Down to trigger an event

Hello everyone, I am currently having a problem developing an app that requires clicking on the Channel Up/Down button. I don’t know the exact key code of those two buttons, I have tried logging on the Simulator but it doesn’t seem to work. I hope everyone can advise me on how to click on Channel Up/Down to trigger an event. Thank you very much.

Channel +/- keys are not available in webOS TV apps. Keycodes for all remote keys available in the app can be found in Magic Remote. Please use one of them. Thank you.