The first alpha test for Diablo 2 Resurrected, the remaster of the original that will add 3D graphics and enhanced visuals and cutscenes, will get under way soon according to Blizzard, and you can sign up for a chance to be a part of it right now.
Simply head over to the Diablo 2 Resurrected website, and log in with your BattleNet account, and you'll be given the option to "opt-in" to the "technical alpha," and you won't even need to pre-order the game to do so.
Speaking to Gamesradar+, the game's producer Matthew Cederquist and designer Robert Gallerani spoke about their plans for the alpha tests, and that there'll be multiple tests between now and the game's release, with the first focusing on PC and single-player. They also confirmed that while they have no specific date for the first alpha just yet, they want it to be "relatively soon" so the team has enough time to act on the feedback they get.
They also suggested there could be multiple testing periods, but cannot confirm how many at this stage. "It really comes down to how much feedback we get. We just want to know how much you guys love the game."