A Simple MERN Full Stack Application

AddDetails.js

import React from 'react';
import axios from 'axios'
import { Link, browserHistory, IndexRoute, BrowserRouter as Router, Route, Switch } from 'react-router-dom';

function AddDetails() {

    const handleSubmit = (e) => {
        e.preventDefault();
        var number = e.target.tel.value
        if (number.length == 10) {
            axios.post("https://user-details-mern.herokuapp.com/details")', {
                Name: e.target.name.value,
                FName: e.target.fname.value,
                Address:e.target.address.value,
                PhonNo:e.target.tel.value,
                Email: e.target.email.value
            })
                .then(function (response) {
                    try {
                        window.location.href = "/"
                    } catch (error) {
                        console.log(error);
                    }
            })
            .catch(function (error) {
                console.log(error);
            });
        }
        else {
            alert("Phone Should be correct")
        }
        
    }

    return (
        <Router browserHistory>
        <div className="form">
            <form onSubmit={handleSubmit}>
                <label>Enter User Details</label>
                <div className="Name">
                    <label>Name</label>
                    <input 
                        type="text"
                        name="name"
                        placeholder="Enter your Name"
                        required
                        />
                </div>
                <div className="FName">
                    <label>Full Name</label>
                    <input 
                        type="text"
                        name="fname"
                        placeholder="Enter your Full Name"
                        required
                        />
                </div>
                <div className="Address">
                    <label>Address</label>
                    <input 
                        type="address"
                        name="address"
                        placeholder="Enter your Address"
                        required
                        />
                </div>
                <div className="PhonNo">
                    <label>Phone Number</label>
                    <input 
                        type="tel"
                        name="tel"
                        placeholder="Enter your Phone Number"
                        maxlength="10"
                        required
                        />
                </div>
                <div className="Email">
                    <label>Email</label>
                    <input 
                        type="email"
                        name="email"
                        placeholder="Enter your Email Id"
                        required
                        />
                </div>
                <input type="submit" onClick="window.location.href=window.location.href" value="Submit" className="submit"/>
                <Link to="/" className="link"><input onClick="window.location.href=window.location.href" type="button" className="btn" value="Go Back"/></Link>
            </form>
            </div>
        </Router>
    )
}

export default AddDetails;

i am getting an error in this file

Like what error your are getting @Shreyachaudhary1112