You can follow these steps:
1. Make sure your Bluetooth headset is paired
with your device.
2. Open the imo beta app on your device.
3. Go to the settings within the app.
4. Look for the option to select the audio source
for calls.
5. Choose your Bluetooth headset as the audio
source for calls.
6. When you make calls in imo beta, the audio
will be routed through your Bluetooth headset.