I am developing an Instagram clone in Kotlin and I want to get photos from Firebase as the user scrolls

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I am developing an Instagram clone in Kotlin and I want to get photos from Firebase as the user scrolls. For example, if I have scrolled through up to 5 photos, I want to fetch 5 more photos from the database, and continue this process until there are no more photos left. I am attaching the code I am trying to write.How can I achieve this?

private lateinit var binding: ActivityFeedBinding
private lateinit var auth:FirebaseAuth
private lateinit var db:FirebaseFirestore
private lateinit var feedAdapter: FeedRecyclerAdapter

private lateinit var postArrayList:ArrayList<Post>

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    binding = ActivityFeedBinding.inflate(layoutInflater)
    val view = binding.root
    setContentView(view)
    auth= Firebase.auth
    db=Firebase.firestore

    postArrayList=ArrayList<Post>()

    getData()

    binding.recyclerView.layoutManager=LinearLayoutManager(this)
    feedAdapter= FeedRecyclerAdapter(postArrayList)
    binding.recyclerView.adapter=feedAdapter

}


private fun getData()
{
    db.collection("Posts").orderBy("date", Query.Direction.DESCENDING).limit(5).addSnapshotListener { value, error ->
        if(error!=null)
        {
            Toast.makeText(this,error.localizedMessage,Toast.LENGTH_LONG).show()
        }
        else
        {
            if(value!=null)
            {
                if(!value.isEmpty)
                {
                    val documents=  value.documents //liste tutuyor
                    postArrayList.clear()
                    for(document in documents)
                    {
                        val comment=document.get("comment") as String
                        val userEmail=document.get("userEmail")as String
                        val downloadUrl=document.get("downloadUrl")as String

                        val post= Post(userEmail,comment,downloadUrl)
                        postArrayList.add(post)
                    }
                    feedAdapter.notifyDataSetChanged()
                    
                }
            }
        }
    }
}

override fun onCreateOptionsMenu(menu: Menu?): Boolean {
    val menuInflater=menuInflater
    menuInflater.inflate(R.menu.menu,menu)

    return super.onCreateOptionsMenu(menu)
}

override fun onOptionsItemSelected(item: MenuItem): Boolean {

    if(item.itemId== R.id.add_post)
    {
        val intent=Intent(this, UploadActivity::class.java)
        startActivity(intent)
    }
    else if(item.itemId== R.id.signout)
    {
        auth.signOut()
        val intent=Intent(this, MainActivity::class.java)
        startActivity(intent)
        finish()
    }
    return super.onOptionsItemSelected(item)
}

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