How to fix a “reload page loop” when using a post method in Node JS?

<form class = "new-date" method = "POST" action = "http://localhost:5600/postDate">
                <h3>Owner</h3>
                <input type ="text" name = "ownerName" class = "form-element global"  id="owner">
                </select>
                <h3>Pet</h3>
                <input type = "text" name = "petName" class = "form-element global" id = "pet">
                </select>
                <h3>Schedule the date</h3>
                <input type="date" id="birthday" name="birthday" class = "form-element global"  id="date">
                <h3>Description</h3>
                <textarea class = "form-element description-text" placeholder= "What is wrong with your pet?" name ="problem" ></textarea  id="problem"><br>
                <input type="submit" class = "form-element btn" value="Add">
</form>

const exp = require('express');
const path = require('path');
var bodyParser  = require('body-parser');
const app = exp();

/*DATABASE AND QUERIES*/ 
const mysql = require("mysql2"); 

var con = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "admin",
    database: "control_clientes",
    connectionLimit: 5
});

app.use(bodyParser.urlencoded());
app.use(bodyParser.json());

app.post('/postDate', (req, res)=>{
    console.log(req.body.ownerName); //TO CHECK IF IM RECEIVING THE DATA. IT WORKS
});