As decribed in this article the console should print out to console in swiftui previews if debug preview is selected. I remember that I used this sometimes. But since I am using Xcode 12, I did not get a single character printed out to console. Is that a bug or was this feature removed?
Console log in SwiftUI debug preview not working with xcode 12
Same issue on my side in Xcode 12.3 (12C33). Seems a bug. At least po something prints to Xcode console in Debug Preview.