Close dropdown with 2nd toggle button

I’m trying to find a simple no-code way to close the top nav menu here. There is one toggle (the square grid button at the top right) that opens it, and I want the ‘x’ that appears in the menu to close it. How can I do this? What am I missing? Menu doesn’t work in the public share link, so please view here…

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