localhost POST not connecting to the database – Reactjs

So I’m having issues making a connection to localhost:3001/insert but I don’t see what the issue may be.

registerdb.js

const express = require("express");
const mysql = require("mysql2");
const app = express();
const db = mysql.createConnection({
  host: "localhost",
  user: "root",
  password: "DanaRoot5!",
  database: "OurProjectSchema",
});
const bodyParser = require("body-parser");
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

app.post("/insert", (req, res) => {
  const body = req.body;
  const sql = `INSERT INTO customer (customer_ID, SSN, address, full_name, date_of_registration) VALUES (?, ?, ?, ?, ?)`;
  const values = [
    body.customer_ID,
    body?.SSN,
    body?.address,
    body?.full_name,
    body?.date_of_registration,
  ];

  db.query(sql, values, (error, results) => {
    if (error) {
      console.log(body);
      console.error("Error executing query: " + error.stack);
      res.status(500).send("Error adding customer");
      return;
    }

    console.log("Query results:", results);
    res.status(200).send("Customer added successfully");
  });
});

app.listen(3001, () => {
  console.log("Server started on port 3001");
});

Register.jsx

import React, { useState } from "react";
const { v4: uuidv4 } = require("uuid");

export const Register = (props) => {
  const [SSN, setSSN] = useState("");
  const [name, setName] = useState("");
  const [address, setAddress] = useState("");
  const handleSubmit = (e) => {
    e.preventDefault();
    const date = new Date().toISOString().slice(0, 19).replace("T", " ");
    const customer_id = uuidv4();

    fetch("http://localhost:3001/insert", {
      mode: "no-cors",
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify({
        customer_ID: customer_id,
        SSN: SSN,
        address: address,
        full_name: name,
        date_of_registration: date,
      }),
    })
      .then((response) => {
        console.log(response);
        if (!response.ok) {
          throw new Error("Network response was not ok");
        }
        return response.json();
      })
      .then((data) => {
        console.log(data);
        // display success message to user
      })
      .catch((error) => {
        console.error(error);
        // display error message to user
      });
  };

  return (
    <div className="auth-form-container">
      <h2>Register</h2>
      <form className="register-form" onSubmit={handleSubmit}>
        <label htmlFor="name">Full Name</label>
        <input
          value={name}
          name="name"
          onChange={(e) => setName(e.target.value)}
          id="name"
          placeholder="Full Name"
        />
        <label htmlFor="SSN">SSN/SIN</label>
        <input
          value={SSN}
          onChange={(e) => setSSN(e.target.value)}
          type="text"
          placeholder="SSN/SIN"
          id="SSN"
          name="SSN"
        />
        <label htmlFor="Address">Address</label>
        <input
          value={address}
          onChange={(e) => setAddress(e.target.value)}
          type="text"
          placeholder="Address"
          id="Address"
          name="Address"
        />
        <button type="submit">Register</button>
      </form>
      <button className="link-btn" onClick={() => props.onFormSwitch("login")}>
        Already have an account? Login here.
      </button>
    </div>
  );
};

So I know that the connection between my local database and the node/express works since I have created an app.get("/select") route and that worked ie localhost:3001/select works.

However, app.post("/insert) does not. I am getting the following message: Cannot GET /insert and in the console I’m getting:

GET http://localhost:3001/insert 404 (Not Found)

I tried testing the localhost:3001/insert with curl but that did not work either.

I also tried playing around with the URL in the fetch statement. But that did not help either.

Both files are on different branches. registerdb.js is on a server github branch and Register.jsx is on a client github branch.

May I please receive some guidance/tips?