When you install the app for the first time, it will step you through establishing LE Bluetooth connections for both aids to the phone. The app uses those connections to communicate with the aids. The app will also separately step you through establishing a regular Bluetooth connection to one aid (by default the right side) designated for phone and audio streaming. You can also do that pairing independently of the app, same as pairing any other BT device. Once finished, the BT connection list in your phone’s settings page should show three connections: two LE connections (one to each side) and one regular BT connection to the side designated for phone and audio streaming. Click on that connection to make sure it’s assigned to phone and audio.
If you have other BT audio devices already, such as wireless headphones etc, then there could be an issue about which device has priority. For example, I have a wireless Android Auto adapter in my car. But it doesn’t work automatically because my aid has priority for BT phone and audio. The easiest way to change that priority is to turn my designated BT aid off, wait a few seconds for the Android Auto adapter to take over the connection, and then turn the aid back on.