When my app ran, everything was fine. But with SwiftUI Preview, Revenue Cat can’t run.
As it relied on the instance of `AppDelegate`, there is no `AppDelegate` in SwiftUI Preview.
```
Purchases.configure(withAPIKey: "api key")
```
Is there a way to set `Purchases.configure(withAPIKey: "api key")` in SwiftUI Preview? Currently I had to comment code so the preview could work.