Add additional page sections to front-page via customizer

Problem: I would like to add additional sections to a child theme based on Twentynineteen, but I'm unable to figure out how!

Tried: I've looked through functions.php, template-functions.php and template-tags.php for something similar to twentyseventeen theme's twentyseventeen_front_page_sections which I figured would be similar in the Twentynineteen theme.

Whenever I search for 'sections' and 'customizer' I end up reading about the 'customizer add sections' which are not what I am looking for.

But no luck.

Desired result: This is ideally where I would like to be able to add new sections which I can then pull into the front page template:

Any hints or links to the correct place where I can find info on this would be much appreciated.

Thank you in advance.

Follow-up: I never fully understood how to add a new section to the homepage display sections of the WordPress Customizer.

In case anyone is interested in how I got around it; I created the layout i wanted with widget areas.

You can read more about Widgetizing themes here: https://codex.wordpress.org/Widgetizing_Themes