Live update room db with rating bar

Im having a RatingBar in my fragment and i need to make it so that when user select any rating, it should update/add to the room db live. after doing so i will move the user to a new fragment. On navigating back i need to get that rating from db and show the user what rating value user has given, and then if user update that again above scenario will proceed.

how can i do this in android kotlin using room db? it will be much helpful if i can get an example. Im using MVVM approach.

The fragment

class CollectFragment : Fragment(), OptionSelectionListener {
 private var ratingBar: RatingBar? = null
...
override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {

        //enabling the transition while entering to this view
        sharedElementEnterTransition = ChangeBounds().apply {
            duration = 400
        }
        return inflater.inflate(R.layout.collect_layout, container, false)
    }
...
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        navController = Navigation.findNavController(view)
        ratingBar = view.findViewById(R.id.ratingBar)

        observeChangesAndUpdateUI(view)
    }
...
private fun observeChangesAndUpdateUI(view: View) {
        ratingBar!!.setOnRatingBarChangeListener { p0, p1, p2 ->
            Toast.makeText(
                context,
                "Given rating is: $p1",
                Toast.LENGTH_SHORT
            ).show()
        }
}
}

I would like if I had a workable example on this and much appreciated.