If you use a template for many blog posts, at some point you will want to change a few details on a template such as changing an image or adding an icon.

To customize a template for a specific post, edit your post normally from the Gutenberg block editor.

Then, in the post settings on the right sidebar, scroll down to the featured image section.

From there, will see the Smart Auto Featured Image section.

Make sure a template is selected. Then click on its thumbnail or on the pencil icon.

This will show up the editor.

Make the desired changes and click “Save for this post”.

You can then Preview the modified template and generate the featured image normally.