The first Public Test Realm for Diablo 4 is now available for play. This PTR will be testing the features and content of Patch 1.4.0, including class changes, a new crafting system, Codex of Power changes, and much more. Players may also submit feedback during this time to identify bugs and other issues with the test build of the game.
Known Issues & What To Expect — Diablo 4 Season 4 PTR Diablo 4 PTR Patch 1.4.0 Patch Notes
While playing on the PTR, players are not required to submit feedback, but it will go a long way to help the developers smooth things over in time for the official release of Patch 1.4.0 on May 14th.
If you wish to submit feedback to help squash bugs and errors, you may do so in many places such as Reddit, the official community Discord server, social media sites, and especially the forums. Blizzard has added two new sections to the Diablo 4 Forum Board specifically for people wishing to contribute.
If you wish to contribute during the PTR and provide feedback or submit bug reports, the official Diablo Forums are the best way to help out.
Diablo 4 PTR Feedback Forum Diablo 4 PTR Bug Report Forum