Siri can read out incoming notifications from many apps without having to unlock your iPhone when you’re using on your Apple Watch.
Go to Siri > Announce Notifications, scroll down, then tap the apps you want audio notifications from.
You can do any of the following:
Say something like “Stop” or “Cancel.”
Press the Digital Crown (AirPods Max).
Note: While listening to a notification, you can turn the Digital Crown to change the volume.
Press either Force Sensor (AirPods Pro and AirPods 3rd generation).
Double-tap either of your AirPods (2nd generation).
Remove one of your AirPods (AirPods Pro and AirPods 2nd and 3rd generation).
If you didn’t turn on Announce Notifications when you set up your AirPods, open the Settings app PDF