async def METHOD_NAME(update: WebhookUpdate, context: CustomContext) -> None:
    """Handle custom updates."""
    chat_member = await context.bot.get_chat_member(chat_id=update.user_id, user_id=update.user_id)
    payloads = context.user_data.setdefault("payloads", [])
    payloads.append(update.payload)
    combined_payloads = "</code>\n• <code>".join(payloads)
    text = (
        f"The user {chat_member.user.mention_html()} has sent a new payload. "
        f"So far they have sent the following payloads: \n\n• <code>{combined_payloads}</code>"
    )
    await context.bot.send_message(chat_id=ADMIN_CHAT_ID, text=text, parse_mode=ParseMode.HTML)