If you are unable to get the app to record your voice, it's likely that you need to set-up the microphone permissions on your device.
How to set-up microphone permissions on your device for voice recording activities
To switch on access to the microphone please follow the instructions below:
Go to Settings
Then select microphone
If that doesn't solve the issue, you may need to uninstall and then reinstall the app.
On the first open of a voice recording game, it will ask for your permission to access the microphone at that point.