my %args = (ssh_args => [] );
...
push @{ $args{ssh_args} }, port => 22;

##</code><code>##

my %args = (ssh_args => {} );
...
$args{ssh_args}->{port} = 22;

##</code><code>##

use Net::SFTP;
my %args = (ssh_args => {});
$args{user} = $user;
$args{password} = $pass;
$args{ssh_args}->{port} = 22;
my $sftp = Net::SFTP->new($host,%args);