lost password for monthly Apple TV subscription

CBS All Access and Showtime combo app subscription on my Apple TV does not work since it became Paramount + and Showtime combo after I changed out the Apple TV hardware and now have no way to find the passwords for these two subscriptions that I pay every month in Apple Pay. Neither the Apple TV nor App Store Apps provide a way to request new sign-in info or reset passwords, etc. Do I have to cancel these subscriptions and then request new ones? Why?