Enabling notifications
From the app’s English Help & Guide · Reference release 1.0.13
Go to More > Notifications. The first time you visit, you'll see an 'Enable notifications' button — tap it to grant Supported permission. iOS will ask once.
If you previously declined the system prompt, the button will jump you straight to Settings so you can enable notifications for Supported there.
Once permission is granted, every person you've added shows up with three toggles. Turn on whichever alerts make sense for that person — you might want low-spoons warnings for someone who frequently overdoes it, but only flare alerts for someone with a more stable condition.