Getting TOC in functions.php / save_post

Hello,
IS there a way to get the TOC in my functions.php file?

Specifically, in the save_post WordPress hook. I have tried this but $toc is “” even though I have 4 H1’s in my post. $ezPost.hasTOCItems is equal to false.
hasTOCItems:false

$toc = $ezPost->getTOC();
$myObj->toc = $toc;

So either my PHP code is wrong or the plugin is not doing something correctly.