This content was released on Nov 3 2020. The official support period is 6-months from this date.
An Alert is a good solution for helping a user avoid an unintentional loss of data. Along with the "sheet", it's another type of modal View.
This is a companion discussion topic for the original entry at https://www.kodeco.com/15234721-your-second-ios-and-swiftui-app/lessons/13