How to unencrypt when on computer with old Mac OS

Neti

I am still running Mac OS 10.15, so there seems to be no version of Boxcryptor available for my laptop. I do have some encrypted files in my Google Drive. I have downloaded a Key. I am not clear how I can unencrypt my files. Would I have to go on a different computer?

Mattis

Neti If you are able doing so, yes, you can use another computer to decrypt your files. You’ll need your key file and the associated password.