It's described in article https://www.screencast.com/t/H4WLdt0oZuV
Where do i Paste the code ?
What do you not understand in instruction? http://rehubdocs.wpsoul.com/docs/rehub-theme/how-to/how-to-add-mailchimp-email-form-to-post-or-page/
It's described in article https://www.screencast.com/t/H4WLdt0oZuV