Using Scaffolding Extensions plugin

After I downloaded this plugin, I am not sure how to use it. According
the doc:

Generally, the scaffolding extensions are used in same way as the normal
scaffolding. Inside a controller, run the command:
scaffold :album

But I tried to run scaffold :control_name, (I have table in the
database) in the app/controller, the system says " scaffold: command not
found"

Suggestion? Thanks in advance,

VW