Android Jetpack navigation - How to pass empty string in navigation arguments?

Question

AnimatedNavHost(navController, startDestination = BottomNavItem.Splash.screen_route){
composable(
            signup + "/{emailFromSignIn}" + "/{passwordFromSignIn}",
            arguments = listOf(
                navArgument("emailFromSignIn"){
                    type = NavType.StringType
            },navArgument("passwordFromSignIn"){
                    type = NavType.StringType
            }
}

navController.navigate(signup + "/$textEmail" + "/$textPassword")

How can i pass empty string?

Error: Navigation destination that matches request NavDeepLinkRequest{ uri=android-app://androidx.navigation/signup// } cannot be found in the navigation graph NavGraph(0x0) startDestination={Destination(0xb6b16c34) route=splash}