Download big file in chunks with plack response

[Thenothing]

Hello everyone I really tried to fix this problem but this time I need his help. This code work to download a file with little size:

use strict;
use warnings;
use Plack::Response;

use Path::Tiny;
use File::MimeInfo;

sub return_psgi {
    my $self = shift;
    my $path_file = shift;

    my $content_type = mimetype($path_file);
    $content_type = 'application/octet-stream' if not defined $content
+_type;
    
    my $content = path($path_file);
    my $content_download = $content->slurp;

    require File::Spec::Unix;
    my $basename = $path_file;
    $basename =~ s|\\|/|g;
    $basename = ( File::Spec::Unix->splitpath($basename) )[2];
    $basename =~ s|[^\w\.-]+|_|g;

    my $response = Plack::Response->new(200);
    $response->headers(
        [
           'Content-Type' => $content_type,
           'Content-Disposition' => qq[attachment; filename="$basename
+"],
        ],
    );

    $response->body($content_download);
    return $response->finalize;
}

But I want to download big files greater of 1GB, so change to download in chunks, to this code:

open (FILE, "< $path_file") or die "can't open $path_file: $!";
binmode FILE;
local $/ = \102400;
while (<FILE>) {
    my $var = scalar $_;
    $response->body($var);
    return $response->finalize;
}
close FILE;

Another intent, using autoflush:

use IO::Handle;

my $BLOCK_SIZE = 1024 * 1024; 
open(my $fh, "<:raw", $path_file) or die "Can't read from input file $
+path_file $!\n";

while (read($fh, $buffer, $BLOCK_SIZE)) {
   
   $response->body($buffer);
   $fh->autoflush;

}
close $fh;

return $response->finalize;

The 2 previous intentions download file a size of kb, corrupt file.

can you please tell me where is my error in my code?