Post Type not working

One of the post types showing up in the options for post type is “Google Calendar Feeds”. I expect that this post type is from a Google Calendar plugin that is installed. I was expecting a notification to go out when I added an event to the Google Calendar which is displayed in a sidebar widget. Any idea why this post type shows up as an option but does not trigger the email notification?

https://ww.wp.xz.cn/plugins/notify-users-e-mail/