Popups plugin uses ‘manage_options’ capability. So you need to add ‘manage_options’ to the editor role and block for it other menu items (like ‘Settings’) prohibited by the same ‘manage-options’ capability with admin menu blocking add-on:
https://www.role-editor.com/block-admin-menu-items
The similar situation was described in this post:
https://www.role-editor.com/wp-statistics-access-other-roles/
