Question about Permalink Setting & WordPress by Yoast Plugin

I have a website not a blog. I’m setting up the WordPress SEO by Yoast plugin. It’s giving me the following warning:

“You do not have your postname in the URL of your posts and pages, it is highly recommended that you do. Consider setting your permalink structure to /%postname%/.” And gave me “Ignore” and a “Fix It” buttons. Which option do I choose?

Do I still need to set this up?

In Settings–>Permalinks, I had Custom Structures set to: /%postname%/
(note the “_”)

Thank you.