Article in English: You can send quick video notes to someone, which are even more simple than a video Snap. To do so, you'll need to open a chat conversation with the person you want to send it to. You'll see a small bubble appear with your video in it. Video notes will always use your forward-facing camera. The recording will be sent automatically if you release the button or use the full 10 seconds. If you need to cancel, drag your finger to the "X" on the screen and then release. Your video note will be sent automatically once you release your finger, or after you've recorded for 10 seconds. Once it's been sent, you can't undo it.

Summary in Vietnamese:
Mở cuộc trò chuyện với người bạn muốn để lại ghi chú. Nhấn và giữ nút Video Camera. Nhấn nút "X" để hủy ghi hình. Thả tay hoặc ghi hình đủ 10 giây để video tự gửi.