Hi there,
I’m not exactly sure I understand what you mean.
You can export most settings here:
https://docs.generatepress.com/article/import-export-overview/#exporting-your-settings
As for Elements (Block, Header, Hook, Layout):
Elements are a post type – so you can use the WordPress Export function to move them.
You then import them on the same option/tool you exported them from.
If you meant, you want to copy the CSS generated from the Customizer settings, perhaps this answer would help:
https://generatepress.com/forums/topic/combine-im-export-with-childtheme/#post-1536729
A wise man once said:
"Have you cleared your cache?"