USE THIS ZIP INSIDE:
/wp-content/themes/pctech-child/

Do not upload this through Appearance > Themes.
Do not extract it one folder above /themes/.
Do not extract a ZIP that creates pctech-child/pctech-child/.

Correct steps:
1. Open hosting File Manager, FTP, SFTP, or SSH.
2. Go to public_html/wp-content/themes/pctech-child/
3. Upload pctech-child-drop-into-existing-theme.zip into that folder.
4. Extract it there. After extract, you should see:
   /wp-content/themes/pctech-child/acf-json/
   /wp-content/themes/pctech-child/assets/
   /wp-content/themes/pctech-child/inc/
   /wp-content/themes/pctech-child/templates/
5. Edit existing functions.php and add these two include files to the
   $pctech_child_includes array:

   'inc/dynamic-data.php',
   'inc/homepage-assets.php',

6. In WordPress admin, open ACF / Custom Fields and sync the new field groups
   if ACF asks.
7. In Bricks, create one Content template for Front Page, add one Code Element,
   then paste the full content from templates/homepage-body.html.

Important:
This ZIP does not include functions.php, so it will not overwrite the current
theme functions.php. You must add the two include lines manually.