Schema Premium plugin has support for schema.org SpecialAnnouncement type that allows you to add schema markups to pages about a Special Announcements on your site.
The “SpecialAnnouncement” type provides for simple date-stamped textual updates, as well as markup to associate the announcement with a situation (such as the Coronavirus pandemic), and to indicate URLs for various kinds of update such a school closures, public transport closures, quarantine guidelines, travel bans, and information about getting tested.
Follow these steps to add the new markup type:
1- Create a new Schema markup
The very first step is to go to Schema > Types, and click on the Add New button.
2- Select schema.org Special Announcement
The next screen will open the quick schema.org creation wizard. Select the schema.org Special Announcement type from the drop down list.
When you are done selecting; Schema Premium will confirm the creation of the new schema.org type, and you will have the choice to go through next steps, which is configuring the schema.org type you’ve selected.
3- Configure schema.org SpecialAnnouncement
Create a set of rules to determine the target of this schema.org type.
For example, you can enable this markup on a specific page or post, or you may have a custom post type for pages about Special Announcements that you would like to enable this type to work on.
3-C- Event Properties
Optionally; this section allows you to configure schema:SpecialAnnouncement properties.
4- Update Schema
Click on the Update button to update schema.org type.
5- Test Structured Data
Test your schema.org markup in Google’s Structured Data Testing Tool to make sure it’s valid. You can test your markup with a simple click.
Here is an article that explains how you can test your schema.