It won't let me add a row to move a div

All I want is a row to move the last div into. When I try to add a row (clicking plus + sign next to rows), it doesn’t appear to add a row - only areas.

How do I add a row to move the last div into?

This area, f, stuff is confusing. Are there any in depth tuts that explain what all this is?

Thanks!

https://preview.webflow.com/preview/dolittle-fab788a5c378d2953699c735dce044?utm_medium=preview_link&utm_source=designer&utm_content=dolittle-fab788a5c378d2953699c735dce044&preview=2ee1628b89ac4adfb27ce16bb2db0503&mode=preview

https://webflow.com/design/dolittle-fab788a5c378d2953699c735dce044

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

https://webflow.com/blog/reuse-grid-layouts-more-easily-with-grid-template-areas