How to reproduce:

1. Create and open a new project

2. Add the In-App Purchasing (com.unity.purchasing) package to the project

3. Import the “Apple App Store - 05 Getting Introductory Subscription Prices” sample

4. Set up the environment by following the guide: https://docs.unity3d.com/Packages/com.unity.purchasing@4.12/manual/UnityIAPAppleConfiguration.html
5. Deploy for testing

6. Observe the result

Expected result: No error is thrown when AppleStoreExtendedProductServive.GetIntroductoryPriceDictionary is called
Actual result: “ArgumentNullException” error is thrown

Reproducible with: 5.0.0 (2022.3.20f1)

Reproducible environment: Windows 11 (reporter)
Not reproducible environment: No other environments tested

Note: CQA could not test the issue, more information in the comments