As your app is not live yet I assume that you're testing on sandbox, I would also recommend reading the details to trouble shoot on this tech note: TN3186: Troubleshooting In-App Purchases availability in the sandbox.
An overview would be:
To offer In-App Purchases in your app, call Product.products(for:) with a list of product identifiers (Product ID) matching these products in the sandbox. Product.products(for:) returns an array that includes an instance of Product for each of the In-App Purchases.
If Product.products(for:) fails to return a Product instance for your products in the sandbox, validate your product identifier list and confirm you set a price and added localizations for each of the In-App Purchases.
After you complete the above checks, retry the product request. If the In-App Purchases are still missing, it may be due to the following reasons:
- Your bundle ID doesn’t match the bundle ID of an app in App Store Connect.
- Your bundle ID is disabled for the In-App Purchase capability in Certificates, Identifiers & Profiles.
- You are using a wildcard App ID for your app.
- You signed your app with an invalid certificate or provisioning profile.
- You have an inactive Apple Developer Program account.
- You don’t have a Paid Apps Agreement in effect in App Store Connect.
- You have incomplete or outdated banking or tax information in App Store Connect.