How to setup Blog Article metafields?

Show Blog Article meta field in your Article page needs to insert the below code in the article.liquid file.
Article file path: Login into Admin panel-> left side menu selects Online store -> select Themes.
Now left sidebar load with file list. Check at Sections bottom of the list “article.liquid” file, click on it.
Insert below code where you want to show the meta field at this position in the file and save it.
{% include 'all-in-one-metafields', metafields: 'article' %}

For a quick view of all the above step check the below image