You don't need the map. AOH is supported:

#!/usr/bin/perl
use warnings;
use strict;

use Text::CSV_XS qw( csv );

my @header = qw( first_name last_name phone );

csv (in => [{ first_name => "Jane",
              last_name  => "Rizzoli",
              phone      => "555-1212" },
            { first_name => "Maura",
              last_name  => "Isles",
              phone      => "555-1515" },
            ],
     headers => \@header,
     );
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Or if you have the hash list already.

my @header = qw( first_name last_name phone );

my @aoh = (
  { first_name => "Jane",
    last_name  => "Rizzoli",
    phone      => "555-1212" },
  { first_name => "Maura",
    last_name  => "Isles",
    phone      => "555-1515" },
    );
csv (in => \@aoh, headers => \@header);
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