How do I know whether the registered email is verified or not in firebase? [python]

@app.route('/register', methods=['GET', 'POST'])
def register_page():
    form = RegisterForm()
    if form.validate_on_submit():
        data = {
            "username": form.username.data,
            "email_address": form.email_address.data,
            "password_hash": form.password.data
        }
        db.collection('users').document(form.username.data).set(data)

        def register():
            email = form.email_address.data
            password = form.password.data
            confirm_pass = form.confirm_password.data

            if password == confirm_pass:
                sign_in = auth.create_user_with_email_and_password(email, password)
                auth.send_email_verification(sign_in['idToken'])  # for email verification
                print("email verification sent")

        register()

        return redirect(url_for('market_page'))
    if form.errors != {}:   # if no errors occur from validators
        for err_msg in form.errors.values():
            print(f'there was an error creating the user {err_msg}')
    return render_template('register.html', form=form)