So, I just enable the Discord Widget and put it in my wiki, and the title said "development-voice-chat", which is obviously one of the voice chat in our Discord server that is not for every members. How does this title thing works? And how do I make it disappear?
That's how Discord displays widgets by default, voice channels are always on top. If you want it to not display at all, you would have to restrict view access to it to a certain role by removing the "View Channel" permission from @everyone.