personalized pass

If you are speaking about being able to edit and layout your own pass (as "personalized pass") then the two places to go are

https://developer.apple.com/library/content/documentation/UserExperience/Conceptual/PassKit_PG/Creating.html#//apple_ref/doc/uid/TP40012195-CH4-SW1

and

https://developer.apple.com/library/content/documentation/UserExperience/Reference/PassKit_Bundle/Chapters/Introduction.html#//apple_ref/doc/uid/TP40012026.

The second link will give you the most information on supported keys.

Thank you for the links. I think now I understand the meaning of personalized pass better. Basically, personalized pass would have different "data" for e.g. icon or images. The pass.json keys will be same. I was thinking that pass.json will support more keys for personalized pass ... e.g. firstname, lastname etc. Because that is the information received from user in sign up form.

I'm sure this comes way too late, but for posterity, I think this is what OP was looking for:

https://developer.apple.com/library/archive/documentation/UserExperience/Conceptual/PassKit_PG/PassPersonalization.html