Data definitions at class scope must specify their value domain

I’m triyng to create class and create variable of this class. I don’t know why I recieved this error.

I have this code:

hi<public> := class():
    New<public> : int = 0
    By<public> : string = ""

MyHi := Material.hi{New := 0, By := ""}

I recieved this error: Data definitions at class scope must specify their value domain.

MyHi : hi = Material.hi{New := 0, By := “”}

try that. you usually have to specify type so i’d think you’d have to specify the class as well