Why my @State doesn't change my conditional statement?

I have a conditional statement to show a @State to the user either to sign in or sign up. When I click on the SignIn$SignUpButton, the @State of the button change but my conditional statement doesn't trigger.

Is there anything missing?

struct CredentialsView: View {

  @State var signInSelected = true
  @State var signUpSelected = false

  @State var firstName = ""
  @State var email = ""
  @State var password = ""
  @State var confirmPassword = ""

  var body: some View {
    VStack {
      SignIn$SingUpButton(signInSelected: signInSelected,
                          signUpSelected: signUpSelected
      )

      VStack(spacing: 30) {
        if signInSelected {
          UserEntryTextField(title: "email", userEntry: email)
          UserEntryTextField(title: "password", userEntry: password)
        }
        else if signUpSelected {
          UserEntryTextField(title: "first name", userEntry: firstName)
          UserEntryTextField(title: "email", userEntry: email)
          UserEntryTextField(title: "password", userEntry: password)
          UserEntryTextField(title: "confirm Password", userEntry: confirmPassword)
        }
      }
      .padding(.top, signInSelected ? 110 : 50)
      Spacer()
    }
    .padding(.vertical, 40)
  }
}