AttributeError: 'LoginForm' object has no attribute 'validate_on_sumbit'

I have done a registration and login page registration page works fine but login page when i Click on create account i get object has no attribute.

application.py

from flask_wtf import FlaskForm
from wtforms import StringField,PasswordField,SubmitField
from wtforms.validators import Length,EqualTo,InputRequired,ValidationError
from models import User
@app.route('/login', methods=['GET', 'POST'])

def login():
    login_form = LoginForm()
    if login_form.validate_on_sumbit():
        return "Logged in, finally!"
    return render_template('login.html', form=login_form)
#wtform_fields.py
class LoginForm(FlaskForm):
    """Login Form """

    username = StringField('username_label',validators=[InputRequired(message="username required")])
    password = PasswordField('password_label',validators=[InputRequired(message="Password required"),invalid_credentials])
    submit   = SubmitField('Login')

login.html

{% from 'form_helper.html' import DisplayField %}

{% extends "prelogin-layout.html" %}

{% block title %} Registration {% endblock %}

{% block content %}

    <h3>Create your account</h3>
    <hr>
    <form action="{{ url_for('index') }}", method="POST" >
       {{DisplayField(form.username, 'Username', autocomplete='off',autofocus=true)}}
       {{DisplayField(form.password, 'Password')}}
       {{DisplayField(form.confirm, 'Confirm Password')}}
        <div class="form-group">
            <input type="submit" value="Create" >
        </div>
        {{form.csrf_token}}
    </form>
   
   
  
{% endblock %}

ErrorLog

in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
  File "C:\Users\Catalyst\Desktop\Python\chatAp\application.py", line 18, in login
    if login_form.validate_on_sumbit():
AttributeError: 'LoginForm' object has no attribute 'validate_on_sumbit'

I'm new at flask can you direct e where I'm mistaken PS I'm working with flaskwtf V1.0.1