Animating Button Title from bottom up, not the default sideways

I would like the button title to appear from bottom up, right now it appears a bit from the left to right and second time a bit from the right to the left. How can I get the desired effect please? Tried .move transition, does not work.

struct TestView: View {
    @State var isNewUser : Bool = true
    
    var body: some View {
        VStack{
            Button {
                isNewUser ?  signUp() :  signIn()
            }
        label: {
            Text( isNewUser ? "create account" : "sign in")
            
        }
        .accentColor(.white)
        .frame(minWidth: 0, maxWidth: .infinity)
        .padding()
        .background( isNewUser ? .red : .green)
        .cornerRadius(10)
        .foregroundColor(Color.white)
        .padding()
            
            Button {
                withAnimation(.easeIn(duration:0.5))
                {
                    isNewUser.toggle()
                }
                
            } label: {
                Text( isNewUser ? "Already have an account? Sign in" : "Do not have an account? Sign up." )
            }
            
        }
    }
    
    func signUp() {
        print("signing up")
    }
    
    func signIn() {
        print("signing in")
    }
    
}