This article explains how to set up Fitbit notifications to mirror some of your smartphone's alerts. These instructions apply to both iOS and Android devices, and all Fitbits with an LCD screen can support phone notifications.
To receive notifications from your iPhone on your Fitbit, your phone's Bluetooth must be turned on, Focus Mode (formerly Do Not Disturb) must be turned off, and both devices must be within close proximity of each other.
On your iPhone, open Settings > Notifications and turn on notifications for the apps you want.
Open the Fitbit app and select the account icon in the top left corner.
