The easiest Powerful Engram you ever got in Destiny 2 is waiting for you to claim, but if you haven't already made your way through Destiny 2: Shadowkeep, you may want to save it for later. As part of its grand transition into Destiny 2 Year 3, including the new expansion and the Destiny 2 Steam transfer, Bungie has overhauled how its Bungie Rewards program works. Each player will have to opt in to the service individually, and Bungie is offering the aforementioned Engram to tempt you into action.
That makes it sound like Bungie is a fairy tale witch trying to lure you into their cauldron, but Bungie Rewards is just the company's way of tracking who is eligible for what physical goodies (and making sure you sign up for their newsletter). The current slate of rewards includes a downloadable template to make your own papercraft Eris Morn mask, unlocked by completing the Shadowkeep campaign, and the right to purchase a commemorative medallion pin by completing all the Season of Opulence Triumphs.
You don't need to do anything tricky or time-consuming like that to get the Powerful Engram, though. Just sign in, head to the Bungie Rewards page, click the "Email Reward" button, and make sure you're opted in to all the required options to get it. Again, you'll want to take care with when you actually claim that Engram.
The Power level of these Engrams is based on your character's current Gear Score, and if you're just sitting at the new minimum of 750, it won't do you much good. You'll be better off waiting until you hit 900, the "soft cap" which can be achieved by playing any game activity, and then redeeming your Powerful Engram to help push you toward the "hard cap" of 950. You'll need all the help you can get if you want to take on the Destiny 2: Shadowkeep raid ASAP.
This is still just the beginning. Bungie says it will launch other franchises and totally transform Destiny by 2025.