vercel is a shorthand for vercel deploy, and vercel kv create ... is attempting to run vercel deploy kv create.... You can check this with vercel kv --help:
vercel kv --help
Vercel CLI 37.14.0
▲ vercel deploy [project-path] [options]
(...)
Perhaps you want to deploy this example instead?
Is there a link where you saw this command by any chance?