Cosmos db Rest API - Error 401 Unauthorized

I'm trying to get a get request to the db cosmos using android, using REST API! The azure cosmos db has a specific heading, but I think everything is correct

However, when I use Http REST API I get the error Unauthorized 401, can you help me?

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    n = findViewById(R.id.teste11);
    Button buttonParse = findViewById(R.id.button_parse);
    buttonParse.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            try {
                getwebservice();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
    client = new OkHttpClient();


}

Getwebservices method

 private void getwebservice() throws Exception {

    String headerDate = getDateString();

    String gen = generateAuthHeader("GET", "docs", "dbs/tempdb/colls/tempcoll/docs/WakefieldFamily",
            headerDate, PRIMARY_KEY);
    final Request request = new Request.Builder()
            .url("https://***.documents.azure.com:443/dbs/***/colls/***/docs/WakefieldFamily")
            .get()
            .addHeader("Accept", "application/json")
            .addHeader("x-ms-version", "2017-02-22")
            .addHeader("Authorization", gen)
            .addHeader("x-ms-date", headerDate)
            .addHeader("cache-control", "no-cache")
            .build();

    okhttp3.Response response = null;
    client.newCall(request).enqueue(new Callback() {
        Headers g = request.headers();
        @Override
        public void onFailure(okhttp3.Call call, IOException e) {
             MainActivity.this.runOnUiThread(new Runnable() {
                 @Override
                 public void run() {
                     String g = "oi";

                 }
             });
        }

        @Override
        public void onResponse(okhttp3.Call call, okhttp3.Response response) throws IOException {
            runOnUiThread(new Runnable() {
                @Override
                public void run() {

                    n.setText(String.valueOf(response.code()));
                }
            });
        }
    });

    }

These are the auxiliary methods for signature and header date

 public String getDateString() {
    SimpleDateFormat formatter =
            new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss 'GMT'", Locale.US);
    formatter.setTimeZone(TimeZone.getTimeZone("GMT"));
    return formatter.format(new Date()).toLowerCase();

}

public String generateAuthHeader(String verb, String resourceType, String resourceId, String date, String masterKeyBase64) throws Exception {

    byte[] masterKeyBytes = Base64.decode(masterKeyBase64, Base64.NO_WRAP);
    Mac mac = Mac.getInstance("HMACSHA256");
    mac.init(new SecretKeySpec(masterKeyBytes, "HMACSHA256"));

    //Build the unsigned auth string.
    String stringToSign = verb.toLowerCase() + "\n"
            + resourceType.toLowerCase() + "\n"
            + resourceId + "\n"
            + date.toLowerCase() + "\n"
            + "\n";

    //Sign and encode the auth string.
    String signature = Base64.encodeToString(mac.doFinal(stringToSign.toLowerCase().getBytes("UTF-8")), Base64.NO_WRAP);

    //Generate the auth header.
    String authHeader = URLEncoder.encode("type=master&ver=1.0&sig=" + signature, "UTF-8");

    return authHeader;
}

I'm still trying to figure out how this works.