By default, the plugin will only allow users with the “Administrator” role access to the plugin settings pages. This means that only administrators can view your Mailchimp API key, edit your sign-up forms and control the various integrations.

If you want to allow other user roles access to the settings pages then you can do this by using a so-called filter hook.

The following code will allow “Editors” to access the Mailchimp for WordPress settings.

add_filter('mc4wp_admin_required_capability', function($capability) {
	return 'edit_pages';
});
Not sure where to add this code? Here's how and where to add code to your WordPress site.

Note that even with this code in place, only users with the administrator role will be able to change the API key. This protects your site from being switched over to another Mailchimp account without the knowledge of an admin.