I have a simple backend that I'd like to return a string of data whenever a POST request is made. The string is converted to JSON, but when I see that the response was successfully received by the client (the browser), the string is missing from the response data in the browser's console.

server.js (the request handler itself is simple, there's just a few dependencies listed)

const path = require('path');
const express = require('express');
const bp = require("body-parser");
const request = require("request");
const {createCanvas, loadImage} = require("canvas");
const cors = require('cors');
const requestIp = require('request-ip');
const { json } = require('body-parser');
const bodyParser = require('body-parser');
const wgServer = express();
const port = 3000;
const fs = require("fs");
const { createContext } = require("vm");

wgServer.use(cors())
wgServer.use(bp.json())
wgServer.use(bp.urlencoded({ extended: true }))
wgServer.use("/public", express.static(path.join(__dirname, 'public')));
wgServer.use(bodyParser.json({limit: '50mb'}))

wgServer.listen(port, function() {
  console.log(`Weatherglyph server succesfully listening on port ${port}.`)
});

wgServer.post('/', async function (req, res) {
  res.set('Content-Type', 'application/json');

... Lots of functions etc irrelevant to the question

let picpath = __dirname + "\\image.png";
  let picbuff = fs.readFileSync(picpath);
  let picbase64 = picbuff.toString('base64');
  console.log(picbase64);
  res.status(201).json({picbase64});
  res.send();
})})

script.js

async function submitCity(){
    let x = document.getElementById("wg_input").value;
    console.log("Successfully captured city name:", x);
    let toWeather = JSON.stringify({city: x});
    console.log("Input data successfully converted to JSON string:", toWeather);
    
    const options = {
        method: 'POST',
        mode: 'cors',
        headers: {'Content-Type': 'application/json'},
        body: toWeather
    }

    fetch('http://localhost:3000', options)
    .then(res => console.log(res))
    .catch(error => console.log(error))
}

Is the data (a .png converted to base64 and sent to the frontend) actually reaching the client and I just can't see it in Chrome's console, or am I sending it incorrectly?