From print:

Note that if you're storing FILEHANDLEs in an array, or if you're using any other expression more complex than a scalar variable to retrieve it, you will have to use a block returning the filehandle value instead:

use warnings;
use strict;
use FileHandle;

my $hashref;
$hashref->{"fh"} =  FileHandle->new(">./test");
print { $hashref->{"fh"} } "Hello\n";
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