Use navigateUp to go back

nagigateUp.kt

@Composable
fun PageB(navController: NavHostController) {
    Column(
        modifier = Modifier.fillMaxSize(),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center
    ){
        Text(
            "Page B",
            color = Color(0xfff44336),
            fontSize = 24.sp,
            fontWeight = FontWeight.Bold
        )
        Button(
            onClick = {
                //navController.navigate("page_a")//not good to go back
                navController.navigateUp()//use navigateUp instead
            },
            colors = ButtonDefaults.buttonColors(
                backgroundColor = Color(0xfff44336),
                contentColor = Color.White
            )
        ) {
            Text("Go back to Page A")
        }
    }
}