Can you please share a link to your website, so we can see your website setup?
For such functionality, we recommend using one of the WordPress ad management plugins. There you should be able to find the feature that you are looking for and much more.
Thanks for the reply.
This plugin gives a short code to add . So how can I place that short code below every article?
It can be done with a custom PHP snippet, we can create it for you (if needed).
Have you tried a plugin like this one? It seems that it may add the ads in some places automatically.