TL'DR

You can configure these settings from the Beeper Desktop by clicking on the Gear icon → Settings → Notifications

Let's break them out:

General:

• You can customize General Notifications settings in this panel.
  • It's possible to toggle which type of notifications you want to result in a notification.
  • It's possible to change the notification sound for each notification type.

Accounts:

• You can also manage notifications per Chat Network.

Notes

For the new Beeper Desktop app notifications to work reliably, it's also crucial to have the correct notification settings in place on the OS level.

Recommended settings on macOS:

Recommended settings on Windows:

• Though there might not be a dedicated setting option for Beeper under System → Notifications, ensure your computer has enabled “Notifications” and notifications for “Apps”.