By activating the TOC, before you finish writing the article, you will be able to see the TOC develop.
It is a relatively simple piece of software that works hierarchically. So headlines with lower ‘rank’ will be indented further.
You will immediately be able to spot if your article is not following a logical path, looking at the TOC.
In both cases below ( Gutenberg and Elementor ) the post should be updated first to make the TOC update.