Schema Premium plugin has support for schema.org FAQPage type that allows you to add schema markups to FAQ (Frequently Asked Questions) pages on your site.
Check out the Schema FAQ Block, it adds more features and layout for your frequently asked questions page.
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 FAQ Page
The next screen will open the quick schema.org creation wizard. Select the schema.org FAQ Page 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 FAQPage
To complete setup, set Location Rules and Properties for this schema.org type to take effect and take care of all the needed technical optimization of FAQ pages on your site.
3-B- Locations
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 FAQ pages or a specific page that you would like to enable this type to work on.
3-C- FAQPage Properties
This section allows you to configure schema:FAQPage properties.
You can add Frequently Asked Questions to the content, then copy & past each Question and its Answer into the FAQ repeated Property field.

Check out the Schema FAQ Block for Gutenberg editor, it adds more features and layout for your frequently asked questions page.
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.