Hello, ldaasdias!
Thanks for posting. The AT&T Unite is designed to provide Wi-Fi connectivity to wireless-enabled devices such as tablets, cell phones, gaming consoles; it does not have a way to connect with an ethernet cable.
In order to connect your MagicJack, you will likely need home internet service such as U-verse. For more information about U-verse Internet, click on the link below.
Let me know if you have any other questions or concerns.
-Mariana