https://store.steampowered.com/sale/2022dovetailpubsale
Watch the livestream today and this weekend from 7 PM UTC on the Steam sale page while logged into Steam. You should receive today's drops after 5-10 minutes. The drops are sellable on the Steam market
New rewards on saturday and sunday (sorry missed first day's rewards yesterday), rewards are visible https://media-cdn.dovetailgames.com/2022/012022/01/Publisher-Weekend-2022-Rewards-Static-1920x1080_V2.jpg.
Full announcement can be read https://live.dovetailgames.com/live/train-sim-world/articles/article/festival-of-rail-live-now-tsw.