Apple Wallet Pass Creation

I'm trying to build my first Apple Wallet Pass and I've been following the tutorial here: https://developer.apple.com/library/archive/documentation/UserExperience/Conceptual/PassKit_PG/YourFirst.html

I get to this point but it fails: To sign and compress the pass, use the signpass tool to sign the pass package. In Terminal, run the following commands: cd ~/Documents ./signpass -p Lollipop.pass These commands create a signed and compressed pass named Lollipop.pkpass in the Documents folder. If the signpass command fails, make sure you are using your correct pass type identifier and check that the pass.json file contains valid JSON.

Here is the error I get from Terminal: 2021-10-21 10:44:11.678 signpass[1461:45126] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'data parameter is nil'

*** First throw call stack:

(

0   CoreFoundation                      0x000000019194f838 __exceptionPreprocess + 240

1   libobjc.A.dylib                     0x00000001916790a8 objc_exception_throw + 60

2   Foundation                          0x00000001926962ec -[_NSJSONReader init] + 0

3   signpass                            0x00000001000fe044 +[PassSigner passTypeIdentifierForPassAtURL:] + 124

4   signpass                            0x00000001000fe4d8 +[PassSigner signPassWithURL:certSuffix:outputURL:zip:] + 1124

5   signpass                            0x00000001000fdc9c main + 864

6   libdyld.dylib                       0x00000001917f1430 start + 4

)

libc++abi: terminating with uncaught exception of type NSException

zsh: abort      ./signpass -p Lollipop.pass

Any help would be appreciate as I would love to create a Wallet Pass for my customers, but can't seem to get past this error.

Thank you, Darren