Certificate verify failed due to recaptcha - python-3.x

Question

I registered recaptcha for my WTForms, and This error **
SSL: CERTIFICATE_VERIFY_FAILED pops up
when i submitted the form.
I registered recaptcha on google with label = localhost and domains = localhost and 127.0.0.1
When I submitted the form after verifying that I'm not a robot, I got redirected to the page with following error:
urllib.error.URLError urllib.error.URLError:
urlopen error [SSL:
CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)
If I set app.config['TESTING'] to True, the form gets submitted just fine.
Here's what my app.py looks like:
from flask import Flask, render_template
from flask_wtf import FlaskForm, RecaptchaField
from wtforms import StringField, PasswordField
from wtforms.validators import InputRequired, Length, AnyOf
app = Flask(__name__)
app.config['SECRET_KEY'] = 'Thisissecret!'
app.config['RECAPTCHA_PUBLIC_KEY'] = '6LdUxpsUAAAAAEKf7HmevAB9-ntHArEovS2pDmOP'
app.config['RECAPTCHA_PRIVATE_KEY'] = '6LdUxpsUAAAAACtXnVVOYTX1M9Hv83jkhzx4KxX1'
app.config['TESTING'] = False
class LoginForm(FlaskForm):
username = StringField('username', validators=[InputRequired(message='A username is required!'), Length(min=5, max=10, message='Must be between 5 and 10 characters')])
password = PasswordField('password', validators=[InputRequired(message='Password is required!'), AnyOf(values=['password', 'secret'])])
recaptcha = RecaptchaField()
#app.route('/form', methods=['GET', 'POST'])
def form():
form = LoginForm()
if form.validate_on_submit():
return '<h1>The username is {}. The password is {}.</h1>'.format(form.username.data, form.password.data)
return render_template('form.html', form=form)
if __name__ == '__main__':
app.run(debug=True)
In my form.html, I have included {{ form.recaptcha }} in the body section.
I expect that the form would submit just fine after the recaptcha validation.