Apple Pay/Freedom Pass
Is it possible to i add my London Transport freedom pass to Apple Pay
iPhone 5c, iOS 8
You'd have to check with the official website for the London Transport Freedom Pass or maybe someone from the UK can help with this.
I noticed this discussion from 2019, but I'm not sure if it's changed since then: Freedom travel pass - Apple Community.
Apple does have this page, maybe it'll be useful for you: Apple Pay - Transport for London - Apple (UK).
I don't know too much about the UK and it's passes, but I hope this answers your question!