I can’t put ad after that specific text

Hello.

I’m trying to put ad in a specific text: “Derechos de imagen”

I have this text in all my posts. I’d like to put an ad after it, but sorry, I can’t understand how the plugin can work for to do this function.

For example, with this post: https://ingenioempresa.com/lienzo-de-propuesta-de-valor/

It was the configuration I put:
Automatic display: after paragraph
paragraph number: 1
Count: From top
Paragraph tags: I don’t put nothing here
and contain: Derechos de imagen

Thank you for your help and sorry if my english is hard to understand.