Real time data stream for after market

I’m using the following code the receive real time data stream using alpaca-py library.
But after and pre market data seems to be unavailable.
Is it the case that premium subscription will provide pre and after market data? or is this just a limitation of their real time datasource?

raw_data = True
async def bar_handler(bar):
mapped_bar = {
BAR_MAPPING[key]: val for key, val in bar.items() if key in BAR_MAPPING

stream = StockDataStream(api_key = API_KEY, secret_key = SECRET_KEY, raw_data=raw_data, feed=DataFeed.IEX)
# stream = CryptoDataStream(api_key = API_KEY, secret_key = SECRET_KEY)

stream.subscribe_bars(bar_handler, "BABA")

DataFeed.IEX my be your problem, I believe only SIP will provide extended hours.