If you're having issues, please follow the steps below:
Before you begin casting
1. Connect your Android device to a Wi-Fi network.
2. The device you are using to cast must be on the same Wi-Fi network as your Chromecast device.
3. You must be running the latest version of the Chromecast-enabled app. You can always double-check that you are on the latest version by visiting the Google Play Store to check for any app updates.
Please note, only external Chromecast is supported at this time.