The solution to this problem is different for iPhone (iOS) and Android phones and to change the volume please follow the steps below:
For iOS: Swipe up on your home screen to access the control center. Next immediately, swipe left to access the Music Volume of your phone (not the same as your phone’s ringtone volume). Make sure that the Music Volume is not set to 0, otherwise you won’t be able to hear your phone ring from Filo.
For Android: Go to Settings > Sound and notifications > Volume > Change the Media Notification Volume / Notification Volume (depending on the Android Model)
Next open the Filo app. Make sure that the Mute setting is not turned on by pressing on the small horizontal lines in the top left hand corner when opening the app and accessing the side panel. If the button to the right of “Mute” appears in green(iOS) or red(Android) it means that the mute function is activated.