TestActivity.kt

class TestActivity : AppCompatActivity() {
    // you can use 'by lazy' in this case, and volley object will be instantiated only when needed 
    private val volleyRequest: RequestQueue by lazy { Volley.newRequestQueue(this) }
    private val testList: MutableList<TestModel> = mutableListOf()
    // you don't need to pass parameters, just need to change a bit the implementation of your Adapter class.
    private val adapter: TestListAdapter = TestListAdapter(this)
    
    // don't need to create this variable if you are not using more than 1 time
    //private var layoutManager: RecyclerView.LayoutManager?=null
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_Test)
           
        setupRecyclerView()
        val HelloLink = "https://www.abc.app"
        getTest(HelloLink)
    }

    
    private fun setupRecyclerView(){
        recyclerViewTest.layoutManager = LinearLayoutManager(this)
        recyclerViewTest.adapter = adapter      
    }
    
    fun getTest(url: String) {
        print("Url Value is:"+url)
        val catRequest = JsonArrayRequest(Request.Method.GET, url, Response.Listener {
            response: JSONArray ->
            try {
                for (i in 0..response.length() - 1) {
                    val catObj = response.getJSONObject(i)
                    val catName = catObj.getString("name")
                    val test = TestModel(name = catName)
                    testList.add(test)
                    Log.d("Name Result==>>", name)
                }
                // call the method update passing the list
                adapter.update(testList)
            }catch (e: JSONException) { e.printStackTrace()}
        },
            Response.ErrorListener {
                error: VolleyError? ->
                try {
                    Log.d("Error:", error.toString())
                }catch (e: JSONException){ e.printStackTrace() }
            })
        volleyRequest.add(catRequest)
}