yapping

To "yap" refers to talking incessantly, often in a way that is annoying, trivial, or boastful. The mental image is that of a small dog barking loudly and continuously, which captures the irritating, high-pitched, or persistent nature of the chatter. It is predominantly used in casual or derogatory contexts to dismiss someone’s speech as unimportant or excessive. You might hear it used to tell someone to stop talking or to describe a situation where someone is rambling on without saying anything of substance.
In conversation
Gaming lobby
Is he still yapping in the voice chat?
Is he still talking non-stop in the voice chat?
Yeah, he won't quit. Mute him.
Yes, he won't stop. Mute him.
Used here to describe someone talking continuously and annoyingly.
Argument between friends
Stop yapping and just show me the proof.
Stop talking nonsense and just show me the proof.
I'm not yapping, I'm explaining!
I'm not talking nonsense, I'm explaining!
Used to dismiss someone's explanation as empty or annoying talk.
Examples
He spent the whole meeting yapping about his weekend plans.
He spent the whole meeting talking incessantly about his weekend plans.
I don't have time to listen to all that yapping; get to the point.
I don't have time to listen to all that empty talk; get to the point.
The commentator wouldn't stop yapping long enough for us to hear the game audio.
The commentator wouldn't stop talking continuously long enough for us to hear the game audio.