Solution for this topic
I hope you are well today and thank you for your question.
I am not sure exactly which Divi plugin you are talking about but if you are referring Divi theme then please note in WordPress at a time you can only activate one theme.
The Jevelin theme comes bundled with Unyson Page builder and WPBakery Page builder plugin which you can use to build pages.
You can use Yellow Pencil plugin to make design changes in the theme as described in the following page.