Problems preparing to transfer apps that are using Apple Login

Hello,

https://developer.apple.com/documentation/sign_in_with_apple/bringing_new_apps_and_users_into_your_team
I know that the "clientsecret" used to get the first "accesstoken" in the process of this document needs to be issued a "Sign in with Apple" key from the Apple developer site.

In the part where you need to select "Primary App ID" when issuing a key
The app does not exist because it was before the app was transferred.

Please let me know if there is another way