You can use the Shortcode using the Post Grid Combo Plugin. This article will help you to use the Shortcode.
To begin, insert a “Shortcode” block.
Click on the Shortcode Key tab.
Here you can select a predefined shortcode of some popular plugins or paste the Shortcode of your own generated Shortcode.
Click on the Choose Button to select the Shortcode of some popular plugins.
Here you can paste or enter a Shortcode.
Now, you can find the preview in the editor section.