Can't insert TOC (greyed out) in Pages 14.1

Hello,

Since iAuthor became Pages, I saved my iAuthor file in pages. I used the styles to define the chapter names and section heading. I can see the TOC on the sidebar, and that works for the pdf.

I'm kind of a newbie with Pages, was tearing my hair out because the text wouldn't continue to the next page. I just learned that I was in the Page Layout version. So I converted to the Word Processing version, and added a fresh page to house the TOC, but the button at bottom of TOC sidebar is still greyed out.

I tried the main tool bar INSERT, and hover over TOC - the 'document' and 'section' options both are greyed out as well. I'm so close to publishing my workbook and am stuck.

Thanks for your help!