File Scavenger operates on a model. You can download the software for free to see if it can locate your lost data, but you will need a legitimate license key to actually save (recover) the files.
If the cost of File Scavenger (approximately $64) is a barrier, there are legitimate alternatives that offer free recovery tiers:
Searching for "cracked" keys or third-party license generators on sites like Google Drive or Mega is highly discouraged. These files often contain: