Portals that ask you to paste a broken link so their backend can "extract" the files are phishing frameworks trying to harvests valid link configurations or serve advertisement tracking scripts.
Strictly speaking, no . Because of the zero-knowledge security, the server itself cannot decrypt the file. However, there are scenarios where the key is accidentally separated from the link, or you can retrieve it through other means. How To Open A Mega Link Without Decryption Key
Often, the key isn't missing; it's just not being recognized properly by the browser. Portals that ask you to paste a broken
megadl 'https://mega.nz/file/RfZAkQyT#6ZlQmg...' the key isn't missing
MEGA’s help center explicitly states: “Contact the person who shared the link and ask them to confirm the correct decryption key or password, or to create a new link.”