Open the dialer app and enter the number that you want to call. If the number you are calling allows you to enter the extension immediately after picking up, the "pause" function will automatically enter the extension after waiting a moment:  Press and hold the * button to add a comma (,) to the end of the number. This symbol indicates a two-second pause before the extension will be dialed. If pressing and holding the * button does not work, tap the (⋮) button next to the number and select "Add pause." If that doesn't work either, tap the number field to open your on-screen keyboard, then type a comma. You can add multiple commas to wait longer. This may be useful for phone systems that have a delay before you can enter the extension. On Windows phones, you'll need to type the comma in another app, copy it, then paste it to the end of the number. Some extensions cannot be entered until the entire automated menu service plays, or until a certain option is selected. The "wait" function will display the extension on your screen and you'll indicate when it should be entered.  Press and hold the # button to add a semicolon (;) to the end of the number. This symbol indicates a "wait," and the subsequent extension will not be dialed until you say so. If you're using a Windows phone, you'll need to add a "w" instead of a ";". This will need to be copied and pasted from another app that allows you to type. After adding the wait or pause symbol, type the extension that you want your phone to automatically dial. Your phone will dial the number. After dialing the number, depending on the symbol you used, it will then either dial the extension you entered (,) or you'll be prompted to indicate when the extension should be dialed (;). If you chose the wait (;) option, you'll be able to navigate to the portion of the menu that allows you to enter the extension first. Once you're in the right part of the menu, tap "Send" in the window to dial the extension. If you dial this extension a lot, you can add the number to your...

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Write a summary of the previous text in Vietnamese:
Quay số mà bạn muốn gọi. Thêm thời gian "tạm dừng" nếu bạn sẽ nhập số nội bộ ngay khi cuộc gọi được kết nối. Thêm thời gian "chờ" nếu số nội bộ chỉ có thể được quay sau khi toàn bộ trình đơn được phát. Nhập số nội bộ theo sau ký hiệu. Gọi số nội bộ. Thêm số với số nội bộ vào danh bạ.