To use the Multiscreen function on your TV, please perform the following steps:
1. To start, make sure your Smart TV and Android phone are connected to the same network
2. Go to home menu and select the "multiscreen" app. The Smart TV will display a unique casting address in the bottom right corner.
3. Open up the "cast" option on your android phone from the drop down quick menu or settings.
4. Select "enable wireless display" from the "more settings" menu in the cast app.
5. The Smart TV will now show up in the list of cast enabled devices. Select the Smart TV from the cast menu that matches the cast address displayed on the TV screen.
6. Once connected the Smart TV will now mirror the content on your Android phone.
Refer to the link below for a video demonstration on using Multiscreen with your Smart TV
NOTE: This process will not work with iPhones or iDevices. An Apple TV is required for mirroring from an iPhone.