Wait, the user mentioned a "free license key," but if it's not available, the article should guide them to proper channels. I need to structure the article to inform, not provide keys. Maybe outline steps to use the trial, and if they can't afford it, suggest alternatives. Also, check if the latest version is V5.21, or if that's an error. Let me confirm the version number. Recuva's latest version as of my knowledge cutoff in 2023 is 1.55. Maybe the user is using V5.21 and wants a license key for it. Regardless, proceed with general info.