RUSH rewards are given to users who have connected certain game accounts to the Player Rush site. These rewards are given for a few different actions those players perform in those games.
To gain RUSH rewards by playing Destiny 2 you must first connect your Destiny 2 account to Player Rush. To see how to do that please check out our article on Connecting Destiny 2 and Player Rush.
Once you have connected your account you can visit your Player Rush Destiny 2 Dashboard.
There you will see your stats and rewards for Destiny 2, as well as the Player Rush Destiny 2 Leaderboard. Player Rush members gain RUSH rewards for killing opponents inside of Crucible matches in Destiny 2.