theme dt-the7 child

I started in the creation of site and I just realized that it is essential to create a child theme. I use the theme The7, I just created the file css and function.php.
My problem is to know which files should I add to the folder theme / dt the 7 child knowing that my site is already existing. indeed my site is finished but I did it on the theme the7 and not on the child theme. As a result, during the updates of the theme, some problems are noticeable during the last update to The7 version 7.3.1. For example, the title bar is no longer the same, etc.
So far I have never encountered a problem, maybe the problem comes from the update of wordpress to guttenberg?

Thank you

Have a nice week end


Thanks for asking your question at Envato forum.

This is your item support

Support for The7 — Multi-Purpose Website Building Toolkit for WordPress

you can contact with that item author @Dream-Theme hope they will solved your issues cause they are most expert on their won builded theme.

If they ask about purchase key then collect from Here

Still have any question open a Envato help ticket from Here