how to get public url from uploaded image from gallery in react native with expo-image-picker?

Question

I'm trying to build an app that give the user to upload and share photos. I'm using react native and expo-image-picker, after user upload photo its give back object with local uri (means that others users couldnt see the image too). I want to send post request to my express server and get back public url that every one could see.

import * as ImagePicker from "expo-image-picker";
import { Platform, Alert } from "react-native";
import axios from "axios";

export default async function getPhotoUri() {
  if (Platform.OS !== "web") {
    const { status } = await ImagePicker.requestMediaLibraryPermissionsAsync();
    if (status !== "granted") {
      Alert.alert("OOPS!", "Premmision denied", [{ text: "fuck" }]);
    } else {
      const result = await ImagePicker.launchImageLibraryAsync({
        mediaTypes: ImagePicker.MediaTypeOptions.All,
        allowsEditing: true,
        aspect: [4, 3],
        quality: 1,
      });
      if (!result.cancelled) {
        console.log(result);
        let dataform = new FormData();
        dataform.append("file", { uri: result.uri, type: result.type });

        const res = await axios.post(
          `${myExpressServerBaseUrl}/photoUploads`,
          { data: dataform },
          {
            headers: {
              "Content-Type": "multipart/form-data; ",
            },
          }
        );

        return result.uri;
      }
    }
  }
}

the result object is:

Object {
  "cancelled": false,
  "height": 1152,
  "type": "image",
  "uri":"file:///data/user/0/host.exp.exponent/cache/ExperienceData/%2540yuvalsilver888%252FLetsGoOut/ImagePicker/0feddf94-cdb5-48d1-9d21-14eae84fbb6b.jpg",  
  "width": 1536,
}

the dataform is:

FormData {
  "_parts": Array [
    Array [
      "file",
      Object {
        "type": "image",
        "uri": "file:///data/user/0/host.exp.exponent/cache/ExperienceData/%2540yuvalsilver888%252FLetsGoOut/ImagePicker/90a663b2-5308-46ce-8f30-6937473dd573.jpg",
      },
    ],
  ],
}

i searched everywhere and couldnt find what to write in the server in the post request to get a public url back (i heard about imgur and tried but faild to make it work)

the backend code is:

const express = require("express");
const app = express();
const cors = require("cors");
const pool = require("./db");
const port = process.env.PORT || 5000;

app.use(express.json());
app.use(cors());

//post local image and give back public url
app.post("/photoUploads", async (req, res) => {
  try {
    const { data } = req.body;ז
    res.json(data);
  } catch (error) {
    console.log(error.message);
    res.json(false);
  }
});