I'm creating this multiplatform educational app that has in-app purchases included. The program was written with Kotlin in Android Studio, the built in AI is Gemini. I asked Gemini to create for me some in-app purchases, but I have no way to see what it looks like. I asked Gemini is there a way for me to preview it before putting in the market. It responded by saying you have to upload the app to the store and set up testing and billing before finding out. I wanted to know if there's a way to preview the each in app purchase before putting in the market. It's a very important question because I don't want to publish it, then have users pay for it when they got nothing in return.