Bundle of Passes not recognised by wallet

I'm following this guide: https://developer.apple.com/documentation/walletpasses/distributing_and_updating_a_pass#3793284

I'm able to create the bundle.pkpasses but when it's downloaded wallet doesn't recognise it. Is there a limit to the OS version for this to work?

I'm trying it out on a iOS v12

Bundle of Passes not recognised by wallet
 
 
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