First, read the English article below.

To do so:  Open your iPhone's Settings. Tap General. Scroll down and tap Keyboard. Make sure Emoji is displayed here. If it isn't, tap Add New Keyboard and then tap Emoji. It's a green app with a white phone icon encircled in white. This option is at the bottom of the screen. If WhatsApp opens to a conversation, first tap the "Back" button in the top-left corner of the screen. This will open the conversation. You can also tap the pencil-and-pad icon in the top-right corner of the screen to formulate a new message. It's the white field at the bottom of the page. If you're starting a new conversation, first tap a contact's name. This is the globe-shaped icon in the bottom-left corner of the iPhone keyboard. If the Emoji keyboard is the only additional keyboard you have, this icon resembles a smiley face. If you have multiple keyboards, you'll need to tap the smiley face icon in the pop-up window above the "Keyboards" icon. You can tap one of the tabs at the bottom of the screen to select specific groups of emojis, or you can swipe left over the emoji keyboard to scroll through all available emojis. It's on the right side of the chat bar. Doing so will send your emoji. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Đảm bảo bàn phím Emoji của iPhone được bật. Mở WhatsApp. Nhấn Chats (Trò chuyện). Nhấn vào một cuộc trò chuyện. Nhấn vào thanh trò chuyện. Nhấn nút "Keyboards" (Bàn phím). Nhấn vào biểu tượng bàn phím Emoji nếu cần. Chọn một biểu tượng cảm xúc. Nhấn vào mũi tên "Send" (Gửi).