use strict;
use warnings;

my %hash = (hello => "Hello World\n", my_function => \&my_func);
my $funcref = $hash{my_function};

&$funcref (\%hash);
$funcref->(\%hash);

sub my_func {
    my $hashref = shift;
    
    print $hashref->{hello}
}

##</code><code>##

Hello World
Hello World