Dumb question here, I've been adding and moving around things in the nav bar and now get that warning. How do I figure out which one or ones need fixing?

I don't want to remove the button. I've done that before and because I have so many links, I cannot figure out which one.

Can you please explain more what this means and how easy it might be to identify and how?

Here's the website: https://www.bodaciousbeardies.com

Thanks much!
Sue