I'm trying to connect to telegram via telethon from Python application

proxy_ip = str('188.166.86.173')
proxy_port = str(1080)
with TelegramClient('anon',
                api_id='123456',
                api_hash='1234567890abcdf',
                proxy=(socks.SOCKS5, str(proxy_ip), proxy_port,True),
                connection=connection.tcpmtproxy.TcpMTProxy
                ) as client:

I get

getaddrinfo() argument 1 must be string or None

I don't understand where I use a wrong parameter