I have an update regarding this.
The renewal message dialog is displayed if we publish the Channel as beta test Channel, but not when the Channel is installed as a zip for development.
We already enabled Billing Testing https://developer.roku.com/en-gb/docs/developer-program/roku-pay/testing/billing-testing.md
Did anyone figured out how "Enhanced Subscription Recovery" feature can be tested with a zip Channel installed through Development Application Installer?