You manage notifications programmatically, using thenotifications API. To use this API you must request thenotifications permission in your manifest.json:

"permissions": ["notifications"]

You then usenotifications.create to create your notifications, as in this example fromnotify-link-clicks-i18n:

const title = browser.i18n.getMessage("notificationTitle");const content = browser.i18n.getMessage("notificationContent", message.url);browser.notifications.create({  type: "basic",  iconUrl: browser.extension.getURL("icons/link-48.png"),  title,  message: content,});

This code creates a notification with an icon, title, and message.

If the notification includes a call to action, you can listen for the user clicking the notification to call the function to handle the action:

browser.notifications.onClicked.addListener(handleClick);

If you are issuing calls to action through notifications, you will also want to define the optional notificationid, so you can figure out which call to action the user has selected.

For details on how to create icons to use with your notification, seeIconography in theAcorn Design System documentation.

Thewebextensions-examples repository on GitHub includes thenotify-link-clicks-i18n example which implements notifications.