我正在尝试使用twitterapi。我在postman中测试了端点，它给出了我需要的正确响应。我在代码中遇到的问题是，它返回一个null作为响应。我相信这是由于我添加不正确的承载令牌到这个android网络api。有人能帮我吗

public class TwitterUserLookUp extends AppCompatActivity {
RecyclerView recyclerView;
EditText userName;
Button search;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_twitter_user_look_up);
    recyclerView = findViewById(R.id.twitterRCV);
    userName = findViewById(R.id.twitterHandle);
    search = findViewById(R.id.userLookUp);
    AndroidNetworking.initialize(getApplicationContext());
    search.setOnClickListener(v -> {
        if (TextUtils.isEmpty(userName.getText())) {
            userName.setError("Twitter Handle is required.");
            userName.requestFocus();
        } else {
            searchFunctionality(userName.getText().toString().trim());
        }
    });
}

public void searchFunctionality(String name) {
    AndroidNetworking.get("https://api.twitter.com/2/users/by/username/" + name)
            .addPathParameter("pageNumber", "0")
            .addQueryParameter("limit", "3")
            .addHeaders("Authorization", "xx")
            .setTag("test")
            .setPriority(Priority.LOW)
            .build()
            .getAsString(new StringRequestListener() {
                @Override
                public void onResponse(String response) {
                    Log.i("Testing", response);
                    Toast.makeText(TwitterUserLookUp.this, "User details: " + response, Toast.LENGTH_LONG).show();
                }

                @Override
                public void onError(ANError anError) {
                    Log.i("test", "test" + anError.getMessage());
                    Toast.makeText(TwitterUserLookUp.this, "Error Occurred: " + anError.getMessage(), Toast.LENGTH_SHORT).show();
                }
            });
}

}