You don't tell us the full error message. Perl also told you, what requires the explicit package name.

Your code is riddled with logical and syntactical errors:

The syntax for accessing or setting a hash entry uses squiggly brackets, not parentheses. Use $args{user} instead of $args(user) which makes no sense.

Some of your lines do not end with a semicolon even though the statement seems to be complete at the line.

You set and declare $user and $password later than you use them. This is likely what Perl complains about. You need to move these lines upwards in your program.

You call Net::SFTP->($host, %args);, but I don't know what it should do. Maybe you can tell us what you expect it to do and where in the Net::SFTP documentation you found that.