Custom fields in OpenCart. What to use?

Question

CMS

Good day. Can you please tell me how in opencart you can make "custom fields", or the so-called "settings pages"? This is necessary to provide the admin with the ability to edit some data throughout the site only from the admin panel, without going into the code. For example, Wordpress has Advanced custom fields for this , etc. And how can this be done in opencart v2.3?
And one more question... For example, I have complex "information pages" with individual layout. Tell me, do they need to be inserted only with "hardcode", or is it possible in opencart, for example, to insert html code into a certain field of this page in the admin panel for subsequent display on the front?

Answer 1

"custom fields"

If we are talking about the admin panel, then custom fields are usually made for a specific task and a module is put under it.
If there is no module, it is not very difficult to add any field through the code, since there are enough manuals in the open spaces. Do a couple of times according to the manual to understand the architecture, and then like clockwork.
In the third, Twig seems to have already appeared, but I'm still trying not to work with 3.
In general, you can also insert code for information pages in the visual editor, so if individual layout is only in the content part of the page, then there should be no problems at all.