OnScrollListener.kt

val lm = binding.recyclerView.layoutManager as LinearLayoutManager
binding.recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
        super.onScrolled(recyclerView, dx, dy)
        val lastVisible = lm.findLastVisibleItemPosition() + 1
        if (viewModel.lastVisibleItem.value < lastVisible) {
            viewModel.lastVisibleItem.value = lastVisible
        }
    }
})