How to cancel a subscription on a different Apple Account when I no longer have access?

how do i cancel a subscription that I purchased on another account that I no longer have access too? I bought my Snapchat + subscription on July 11th 2024 and when I got my new phone I got a new account and now I can’t access the old one and I can’t cancel the subscription.

[Re-Titled by Moderator]

Original Title: Accessing A Subscription on another account