The thread is closed because as i told you there is no possible way to add widgets to the header.
Unfortunately i can’t help you with a code that i can’t see, and specifically with a code that we didn’t write.
There is nothing special with the child themes, just duplicate the file with the same path and you should get it working, no need to require the file again, Just make sure from the file path as i noticed that you are adding the file in the theme folder directly from what you wrote here ” get_stylesheet_directory() . ‘/header-text-block.php’ ); ”
I hope that this helps