So I've managed to have single pkpass working with download button. However I am looking for solution that let's you download multiple passes at once for example for multiple legs tickets.
there is that: https://developer.apple.com/documentation/walletpasses/distributing_and_updating_a_pass
which says:
Provide a bundle of passes to enable your user to download multiple passes at once. To create the pass bundle: Create a .zip file containing the .pkpass files for the passes that are part of the bundle. Change the extension of the .zip file to .pkpasses. You can distribute a bundle of passes the same way you distribute a single pass. The MIME type for a bundle of passes is "application/vnd.apple.pkpasses".
But I did that and it's seen as a generic file download, and not opening with passbook. Is there a a way to do it ?
I found out, it will be available for IOS 15. so it's a future feature. https://developer.apple.com/videos/play/wwdc2021/10092/