Unable to transfer subscription to a new phone – Walking Weight Loss: WalkFit Review

I bought 1 year subscription on my iPhone 12. My iPhone 13 came today and when I opened the app on my iPhone 13 I had to go through the whole sign up again since there’s no login screen. I went through the whole process of entering my goal and my body statistics again but it won’t let me continue since it recognizes that I do have 1 year subscription but I couldn’t click continue. I’m stuck and cannot transfer my subscription from my old phone to my new phone.
Review by Lohan&Cyrus on Walking Weight Loss: WalkFit.