Passing parameters and Headers using Volley

Question

I am trying to authenticate with twitter and display my twitter feed in app using a Volley request. Where i can do this if I assign my String URL with the parameter I want to assign it using the getParam() method. However, if i set the URL without the extra parameter and use the getParam(). It fails with a 401?

 public class MainActivity extends AppCompatActivity {
    private ArrayList<MyTweet> tweets = new ArrayList<MyTweet>();

    private TextView post_reponse_text;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button post_request_button = findViewById(R.id.test);
        post_reponse_text = findViewById(R.id.get_response_data);

        post_request_button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                postRequest();
            }
        });
    }


    private void postRequest() {
        RequestQueue queue = Volley.newRequestQueue(MainActivity.this);
        //String url = "https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name=realScreenName";
String url = "https://api.twitter.com/1.1/statuses/user_timeline.json";
        final StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        try {
                            // post_reponse_text.setText("Post Data : " + response);
                            post_reponse_text.setText("Twitter Feed");
                            JSONArray jsonArray = new JSONArray(response);

                            for (int i = 0; i < jsonArray.length(); i++) {
                                JSONObject session = jsonArray.getJSONObject(i);

                                MyTweet tweet = new MyTweet("might need to remove", "this also");
                                tweet.content = session.getString("text");
                                tweet.author = session.getString("id_str");
                                tweets.add(tweet);
                            }

                            /*Send to Adapter*/
                            RecyclerView recyclerView = findViewById(R.id.my_recycler_view);
                            RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getApplicationContext());
                            recyclerView.setLayoutManager(layoutManager);
                            MyTweetsAdapter Adapter = new MyTweetsAdapter(tweets);
                            recyclerView.setAdapter(Adapter);

                        } catch (Exception e) {
                            e.printStackTrace();
                            Log.v("Error:", "Error Creating JSON object");
                        }
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                post_reponse_text.setText("Failed to find Twitter feed");
            }
        })
        {
            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap <String, String>();
                String name = "realScreenName";
                params.put("screen_name", name);
                return params;
            }
            @Override
            public Map<String, String> getHeaders() throws AuthFailureError {
                Map<String, String> params = new HashMap<String, String>();
                params.put("Authorization", "OAuth oauth_consumer_key=\"realKey\",oauth_token=\"realKey\",oauth_signature_method=\"HMAC-SHA1\",oauth_timestamp=\"1591115128\",oauth_nonce=\"oEbfgtjeKwA\",oauth_signature=\"realKey\"");
                return params;
            }
        };
        queue.add(stringRequest);

    }