Setting the price and testing the Apple connect in-app purchase?

Question

iOS

I figure out how to test the presence of in-app purchases through react-native-iap, I added subscriptions, I try to request a list using

const products = await RNIap.getProducts(productIds);

But an empty array is returned. There is a feeling that Apple test subscriptions take time to create them (weird). How long do you have to wait?
Also, when will I be able to indicate the price in the subscription? Now I’m opening the subscription settings, and there you can select only the category of taxation, localization, info for promotion and info for verification (all fields, except for taxation, are disabled)