Develop a module for opencart 3

you want to add a banner line to the site http://joxi.ru/DrlLpYnTKy4dwr.

it seems to already exist, but I dont really understand how it was added or just thrown into the template file or is displayed somewhere from the admin panel.

It is necessary to make several such lines with different text and so that when updating the page, a new one appears. As an example, you can see the https://www.klenmarket.kz/ - they have several banners close one, update the page and a new banner line comes out there.

CMS Opencart 3