Looking for After hours trading

I have a small Robinhood account that allows after hour trading, in other words between 4 and 8 PM and in the morning I believe it starts at 7 AM until 9:30 AM. My brother and I do a bit of stock trading as a friendly competition on a daily or every other day basis. We both are with Vanguard with the majority of our funds. We cannot seem to do any after hour trades with Vanguard even though Google says they do it. We’re wondering if other brokerage firms do allow it and actually do let you do it