A. 1. Ensure your Bluetooth headset is fully charged and turned on. 2. Go to your device's Settings > Bluetooth. 3. Find your headset in the list of paired devices and tap on it to reconnect. 4. If it still doesn't work, try unpairing the headset and then pairing it again. 5. Restart your phone and check if the audio is now routed to the headset.
B. 1. Check if the audio output is set to the Bluetooth headset. During a call, tap on the audio icon (usually a speaker or Bluetooth symbol) and select your headset. 2. If the issue persists, reset your Bluetooth settings by going to Settings > System > Reset options > Reset Wi-Fi, mobile & Bluetooth.