While websites may list long strings of characters as "working keys," using them can lead to several issues: Malware & Spyware:
: Official activation keys are unique to a single purchase and are validated against Movavi’s servers. Once a key has been used by another person, it is typically blocked from further use. Security Risks Movavi Activation Key Free Copy And Paste
If you previously bought Movavi but lost your key, you don't need to find a "free" one online. You can retrieve it officially: While websites may list long strings of characters