please help

I need help with python reflex get var from js script and send to Reflex

I testing it and get answer from alert

import reflex as rx

class TelegramState(rx.State):
    username: str = ""
    
    def update_username(self, username):
        self.username = username
        rx.logging(self.username)

def index() -> rx.Component:
    return rx.container(
        rx.script(src="https://telegram.org/js/telegram-web-app.js"),
        rx.button(
            TelegramState.username,
            on_click=rx.call_script(
                """
                const initData = window.Telegram.WebApp.initData;
                const initDataObj = Object.fromEntries(new URLSearchParams(initData));
                const username = JSON.parse(initDataObj.user || '{}').username || "";
                alert("Init Data: " + username);
                Reflex.store.TelegramState.update_username(username);
                """
            ),
        ),
        rx.text(TelegramState.username),
    )