
Explanation:

Box 1: Perform user acceptance testing
Go-live Readiness Review prerequisites
The project team should validate solution readiness. The following prerequisites must be met before the Go- live Readiness Review with Microsoft can be initiated. The production environment can be deployed after the Go-live Readiness Review with Microsoft has been successfully completed.
* User acceptance testing (UAT) and performance testing have been completed or almost completed in a Tier-
2 (or higher) environment.
* Etc.
Box 2: Enter a Go-live date
The go-live date in LCS correctly represents the go-live date that you're targeting. This date is the date when end users will start live operations, not cutover activities.
Reference: https://docs.microsoft.com/en-us/dynamics365/fin-ops-core/fin-ops/imp-lifecycle/prepare-go-live