Put it right after the message appears on screen, once viewers have had a moment to read it. Open with the Keyboard Typing Sound to show the text being written, then follow this clip with the Shocked Meme Sound when the other person finally notices what was there all along.
關於此聲音
This is a short spoken clip centred on the Indonesian phrase 'baca aja', lasting about four seconds. It feels like a playful, slightly teasing nudge to stop asking and look at the words already given. That direct, light-hearted edge makes it useful as a quick reply when a message, caption or note already contains the answer.