This particular file name follows the naming convention used by certain niche gaming communities or developers sharing early "builds" of indie horror projects. To help you further, could you clarify a few things?
If you are looking for a specific soundtrack or asset from that build, let me know. FrightDiary Build 03152023.rar
Often, the password (or "piece") is posted in the original forum thread, Discord channel, or Patreon post where the link was shared. This particular file name follows the naming convention