In the KDP Help pages under "External Links" it says "Links to web forms that request customer information (e.g., email address, physical address or similar)"are prohibited (see screenshot).
But, I see tons of authors (including very successful independent publishers) that have a lead magnet link at the front of their book with a link to a landing page that collects emails to get the bonus.
According to what it says in the KDP Help pages (see screenshot) are we really allowed to have a lead magnet link inside our ebook and paperback that requires an email address in order to get the bonus book? I don't know how we'd collect emails without it, so I just needed clarification on this.