eclplot command

Hello dear, Please I learn how to use eclplot command.
From Stata help, I run the example:

. sysuse auto,clear
. parmby "xi:regress mpg i.foreign i.rep78", label norestore
. sencode parm,gene(parmid)
sencode mpg foreign rep78, gene(foreign rep78)
. eclplot estimate min95 max95 parmid

But I get error about 2nd line : "variable parm not found"

I don't know how to fix the issue?

Can we help me please?


Thk you