Flask-WTF - Unable to test a form submission

I would like to test a wtf-form with a crsf token but I don't know how to send the token.

Here is my form :

class myLoginForm(FlaskForm):
    username = StringField()
    password = StringField()
    mySubmit = SubmitField('Save')

Here is my route :

@app.route('/login', methods=['GET', 'POST'])
def login():
    loginForm = myLoginForm()

    if loginForm.validate_on_submit():
        result = request.form
        username = result.get("username")
        password = result.get("password")

Here is my test :

import unittest
from flask_testing import TestCase
from flask import Flask
import json

class TestLogin(TestCase):

    def create_app(self):
        app = Flask(__name__)
        return app

    def test_submission(self):
        headers = {
            'ContentType': 'application/json',
            'dataType': 'json'
        }
        data = {
            'username': 'foo',
            'password': 'bar'
        }

        response = app.test_client().post(
            '/login',
            data=json.dumps(data),
            content_type='application/json',
            follow_redirects=True
        )

        assert self.get_context_variable("loginForm").validate_on_submit() == True

The assertion fails, because the validate_on_submit() returns False. I think it is due to the crsf token.

How can I send the crsf token to the POST request ?

Have a nice day

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