初めてアプリ内課金を実装して審査依頼をしたところ、リジェクト（泣）
Guideline 2.1 - Performance - App Completeness
We are unable to complete the review of your app because one or more of your in-app purchase products have not been submitted for review.
Next Steps
To resolve this issue, please be sure to take action and submit your in-app purchases and upload a new binary in App Store Connect so we can proceed with our review.
Resources
Learn more about how to offer in-app purchases in App Store Connect Developer Help.
Please see attached screenshots for details.
App Store ConnectのApp内課金とサブスクリプションが選択されていなかったことが原因。
選択したら無事審査通りました！