How to exchange variable between ReactJS and Python script

I have a ReactJS application that has the following workflow:
user submit input -> send input to Python script (with python-shell npm package) for computing result -> store the returned result to firebase.
PS: The Python function couldn't be re-written in Javascript.

User submit input:

<div className="post_container">
    <div className="input">
        /* User submit the input -> compute result -> store to firebase*/
        <form>
            <input value={input} onChange={e => setInput(e.target.value)} type="text"></input>
            <button onClick={sendPost} type="submit">Submit</button>
        </form>
    </div>
</div>

A Javascript function that calls the Python file:

const computeResult = () => {
    let result;

    /* Python script has a function that computes the result */
    let python = new PythonShell('script.py');
    
    python.send(input); /* send the input to the script */

    python.on('message', function (message) {
        console.log(`Message received from Python: ${message}`);
        result = message; /* receive the computed result from the script */
    });

    python.end(function (err,code,signal) {
        if (err) throw err;
        console.log('The exit code was: ' + code);
        console.log('The exit signal was: ' + signal);
        console.log('finished');
    });

    return result;
}

Store the result to firebase:

const sendPost = async(e) => {
    e.preventDefault();
    /* Compute the result by calling computeResult()*/
    let result = await computeResult();
    
    /* Store the result to the firebase */
    db.collection('posts').add({
        time: firebase.firestore.FieldValue.serverTimestamp(), 
        result: result
    })

    setInput(''); 
}

The full code is as shown below:

import React, { useEffect, useState } from 'react';
import { db } from './firebase';
import firebase from 'firebase';
import {PythonShell} from 'python-shell';

function Post() {
    const [input, setInput] = useState('');

    /* A function that calls Python script */
    const computeResult = () => {
        let result;

        /* Python script has a function that computes the result */
        let python = new PythonShell('script.py');
        
        python.send(input); /* send the input to the script */

        python.on('message', function (message) {
            console.log(`Message received from Python: ${message}`);
            result = message; /* receive the computed result from the script */
        });

        python.end(function (err,code,signal) {
            if (err) throw err;
            console.log('The exit code was: ' + code);
            console.log('The exit signal was: ' + signal);
            console.log('finished');
        });

        return result;
    }

    const sendPost = async(e) => {
        e.preventDefault();
        /* Compute the result by calling computeResult()*/
        let result = await computeResult();
        
        /* Store the result to the firebase */
        db.collection('posts').add({
            time: firebase.firestore.FieldValue.serverTimestamp(), 
            result: result
        })

        setInput(''); 
    }

    return (
        <div className="post_container">
            <div className="input">
                /* User submit the input -> compute result -> store to firebase*/
                <form>
                    <input value={input} onChange={e => setInput(e.target.value)} type="text"></input>
                    <button onClick={sendPost} type="submit">Submit</button>
                </form>
            </div>
       </div>
    )
}

export default Post

When I run npm start, no error message displayed in the terminal. Instead the error message occurs in localhost:3000. I've no clue how I can solve this error.

TypeError: The "original" argument must be of type Function

promisify
node_modules/util/util.js:601
  598 | var kCustomPromisifiedSymbol = typeof Symbol !== 'undefined' ? Symbol('util.promisify.custom') : undefined;
  599 | 
  600 | exports.promisify = function promisify(original) {
> 601 |   if (typeof original !== 'function')
  602 |     throw new TypeError('The "original" argument must be of type Function');
  603 | 
  604 |   if (kCustomPromisifiedSymbol && original[kCustomPromisifiedSymbol]) {