If you want to display the default featured image in structured data if there is no featured image then you can follow the below steps to set up the default featured image.
1. First go to WordPress Admin Area -> Structured Data -> Settings -> Global -> Click on Default Data option.

2. Default Image: In this field, you have to upload the default image which you want and if you did not set the featured image then this image will be displayed by default.
3. Default Post Image Width: In this field, you can give default post image width.
4. Default Post Image Height: In this field, you can give default post image Height.
5. Click on the “Save Settings” button.
In the source code, JSON schema markup will be added like below the screenshot.

That’s it for this tutorial!
We hope it helped you. If you have any feedback or questions or do you want us to create compatibility for any other schema type which isn’t listed in our plugin then you can request us we will surely implement it as soon as possible.
Just contact us here and we are always available for you.