async def check_membership(user_id, bot):
    member = await bot.get_chat_member(CHANNEL_USERNAME, user_id)
        return member.status in ["member", "administrator", "creator"]
    
async def start(update: Update, context: ContextTypes.DEFAULT_TYPE):
    user_id = update.effective_user.id
    
    if await check_membership(user_id, context.bot):
        await update.message.reply_text("✅ Welcome! You can now use the bot.")
    else:
        keyboard = [
            [InlineKeyboardButton("Join Channel", url=f"https://t.me/{CHANNEL_USERNAME[1:]}")],
            [InlineKeyboardButton("I've Joined", callback_data="check_join")]
        ]
        
        reply_markup = InlineKeyboardMarkup(keyboard)

        await update.message.reply_text(
            "🚫 You must join our channel before using this bot.",
            reply_markup=reply_markup
        )