Tickets for the Skyline grandstand sold out quickly on the official website. So if you still want tickets, I’d recommend buying tickets through StubHub, where there’s always a good selection available right up until race day. Sometimes you can find them at lower prices as well, plus there are lots of one day ticket options available.
I’ve bought all my F1 tickets through StubHub over the last few seasons and have had a positive experience dealing with them each time. Their FanProtect guarantee is great for peace of mind too, as it ensures your tickets and money are safe.