Install free software like 7-Zip or WinRAR. Right-click the file and select "Extract Here" or "Open". macOS: Use apps like The Unarchiver or Keka .
Use an online archive extractor if the file is not confidential. alizia.7z
Otherwise, please tell me what you're trying to achieve with this file, and I can guide you further. Install free software like 7-Zip or WinRAR