While directly attaching a ZIP file to a PDF isn't currently possible, there is an alternative approach to achieve your desired outcome: include the ZIP file as a link within the PDF. Here's how:
Upload the ZIP file to a cloud storage service (e.g., Google Drive, Dropbox).
Share the file as a link and grant appropriate access permissions.
Within your PDF, insert a hyperlink using the desired text or icon. Link it to the shared cloud storage link.