Making a call is the same whether on cellular or Wi-Fi. From the home screen, select the 
 Phone app > dial the desired number > select the Call icon. When Wi-Fi Calling is enabled the Call icon will change to the Wi-Fi Calling icon.
Note: To make or receive calls from your tablet, you must update your device to the most current software version and set up NumberSyncTM.
Wi-Fi Calling
Samsung Galaxy Tab A7 Lite (SM-T227U)
Wi-Fi Calling
Use your Wi-Fi connection to talk and text when cellular coverage is limited or unavailable.
INSTRUCTIONS & INFO
Wi-Fi Calling is turned on as part of the activation process. To use Wi-Fi Calling, you'll need a Wi-Fi Internet connection and a postpaid AT&T wireless account provisioned with HD Voice. Certain restrictions, requirements or limitations may apply. Visit About Wi-Fi Calling or att.com/wificalling for more details. When your phone is connected to Wi-Fi, Wi-Fi Calling is on, and a cellular connection is unavailable or poor, calls will be carried over Wi-Fi.