1krBlocker uses separate kinds of notifications, so you can set each one's sound and style in Android:
- Messages: safe and low-risk messages, with sound.
- Quarantine: quiet notices that messages were moved to quarantine.
- Summary: the daily summary.
- Alerts: important warnings, for example a link you received being found dangerous later.
Open Settings → Notification sounds and channels (or the phone's Settings → Apps → 1krBlocker → Notifications) and tap a kind to change its sound, vibration or importance.
Keep Alerts on: they tell you about danger in messages you already have. Very risky messages never notify you, on purpose.