This extension is no longer maintained or is it necessary. YouTube has built-in keyboard shortcuts now: https://support.google.com/youtube/answer/7631406?hl=en
Cross-tab keyboard control of youtube video and playlist playback
This extension is no longer maintained or is it necessary. YouTube has built-in keyboard shortcuts now: https://support.google.com/youtube/answer/7631406?hl=en
Cross-tab keyboard control of youtube video and playlist playback