I have a free trial set up like so in Google Play:
I query the product details using this code:
final Set<String> productIDs = <String>{
"ad_monthly",
"ad_semi_annual",
"ad_annual",
};
final ProductDetailsResponse response =
await InAppPurchase.instance.queryProductDetails(productIDs);
which returns
I/flutter (18343): freeTrial: ad_annual
I/flutter (18343): response: 3
I/flutter (18343): Product Details:
I/flutter (18343): ID: ad_annual
I/flutter (18343): Title: Audio Diary Annual Plan (Audio Diary: AI Voice Journal)
I/flutter (18343): Description:
I/flutter (18343): Price: £24.99
I/flutter (18343): Raw Price: 24.99
I/flutter (18343): Currency Code: GBP
However, when I go to buy it on development mode the free trial does not show up.
I'm not sure if this will work in production, and not sure how to test if it would as I don't have a real Android device. The free trials work for the Apple app with no configuration.
EDIT: I built the production APK and installed it on the emulator with adb, however even though it is the production version of my app.. it still is offering me 30 mins for the yearly version, 5 mins for the monthly version, etc.