Play games
Choose the game that interests you and play itfor free.
Complete the quests
Every game has some quests for which you will receive Soul Gems.
Receive rewards
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
When I try to open my steam daily chest I get a pop up telling me to add my steam link to my settings. My steam link is already in my settings, that's how I got the steam chest.