from telethon import TelegramClient
import asyncio
import threading







async def send_message():
    loop = asyncio.new_event_loop()
    api_id = 555
    api_hash = '555555555'
    client = TelegramClient('55555555.session', api_id, api_hash, loop=loop)
    async with client:
        await client.send_message('+55555555', '123')





def go():
    asyncio.run(send_message())


threading.Thread(target=go).start()