I'm new in react native. I'm learning it but I'm facing an issue working on expo document picker. I use the document picker, but it does not display anything showing or sometimes gives a promise rejection error.
I'm stuck at it for a long time today.

upload.js

import React, { useState } from "react";

import {

  StyleSheet,

  Text,

  View,

  TextInput,

  Button,

  TouchableOpacity,

} from "react-native";

import * as DocumentPicker from "expo";



const UploadFile = () => {

  pickDocument = async () => {

    let result = await DocumentPicker.getDocumentAsync({});

    console.log(result.uri);

    console.log(result);

  };



  return (

    <View style={styles.background}>

      <Text style={styles.file}>Upload CSV File</Text>

      <View style={styles.button}>

        <TouchableOpacity>

          <Button

            title="upload your file"

            color="black"

            onPress={pickDocument}

          />

        </TouchableOpacity>

      </View>

    </View>

  );

};



const styles = StyleSheet.create({

  background: {

    backgroundColor:

      "radial-gradient(ellipse at left bottom,    rgb(163, 237, 255) 0%,    rgba(57, 232, 255, 0.9) 59%,    rgba(48, 223, 214, 0.9) 100% )",

  },

  file: {

    color: "black",

    marginHorizontal: 145,

  },

  button: {

    marginHorizontal: 60,

  },

});



export default UploadFile;

I want to upload a file.