To enable task notifications, a system administrator will need to enable Reminder Sets by adding this option to the page layout. Instructions in this article will step you through the process.

1. First, ensure that Show task reminders in Lightning Experience is enabled in each user's personal settings. Users will need to enable this individually in their personal profile by clicking on their profile picture in the upper right, then clicking Settings. Navigate to Calendar & Reminders > Activity Reminders. Make sure the box next to Show task reminders in Lightning Experience is checked, then click Save.

2. Next, go to Setup > Global Actions select Layout next to New Task.

3. Then, drag and drop Reminder Set onto the page layout, then click Save.

4. After refreshing your browser, Reminder Set will be shown in the Activity panel under New Task.