I'm trying to make a login system which is part of my project with react, express, MySQL and Axios but I keep getting this error- Uncaught (in promise) Error: Request aborted

Server side:

const express = require("express");
const cors = require("cors");
const mysql = require("mysql");

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

const db = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "cool12345",
    database: "users"
})

db.connect(err => {
    if(err){
        return err;
    }
})

console.log(db)


app.post("/register", (req, res) => {
    const username = req.body.username;
    const password = req.body.password;
    const email = req.body.email;

    db.query("INSERT INTO teachers (name, email, password) VALUES (?,?)", [username, email, password], (error, result) => {
        console.log(error)
    })
 
    db.query("INSERT INTO teachers (name, email, password) VALUES ('test', 'test2', 'test3')")
})
 

app.listen(4000, () => {
    console.log("Listening on port 4000")
})

client side:

import React, { useState } from 'react'
import "../styling/SignUp.css";
import { useHistory } from "react-router-dom"
import Axios from "axios";



function SignUp() {
    const [usernameReg, setUsernameReg] = useState("")
    const [emailReg, setEmailReg] = useState("")
    const [passwordReg, setPasswordReg] = useState("")

    const register = () => {
        Axios.post("https://localhost:4000/register", {username: usernameReg, email:emailReg, password: passwordReg}).then((response) => {
            console.log(response)
        })
    }

the function in the client-side returns a form but there's too much code so I left it out of this question. The signup button has an onClick handler function which runs the register.