You could try something like this:

#!/usr/bin/perl

use Term::ReadKey;

my %seqs = (
            "\e[A"  => "Up",
            "\e[B"  => "Down",
            "\e[C"  => "Right",
            "\e[D"  => "Left",
            "\e[5~" => "PgUp",
            "\e[6~" => "PgDn",
            # ...
           );

ReadMode 4;  # raw mode

my $buf = '';

while (my $key = ReadKey()) {
    
    last if $key eq 'q';      # hit 'q' to quit loop

    $buf .= $key;
    $buf = substr($buf, -4);  # keep last 4 bytes
    
    my $escseq = substr($buf,rindex($buf,"\e"));

    if (exists $seqs{$escseq}) {
        print "$seqs{$escseq}\n";
    }
}
ReadMode 0;  # reset tty
[download]

(There are a few subtle issues with this approach, but it should give you an idea how to approach the problem...)

update: you could also use a dispatch table to execute subs when a certain key is pressed:

#!/usr/bin/perl

use Term::ReadKey;

my $n;

my %seqs = (
            "\e[A"  => sub { $n++;      },   # Up
            "\e[B"  => sub { $n--;      },   # Down
            "\e[C"  => sub { $n += 10;  },   # Right
            "\e[D"  => sub { $n -= 10;  },   # Left
            "\e[5~" => sub { $n += 100; },   # PgUp
            "\e[6~" => sub { $n -= 100; },   # PgDn
           );

ReadMode 4;  # raw mode

my $buf = '';

while (my $key = ReadKey()) {
    
    last if $key eq 'q';      # hit 'q' to quit loop

    $buf .= $key;
    $buf = substr($buf, -4);  # keep last 4 bytes
    
    my $escseq = substr($buf,rindex($buf,"\e"));

    if (exists $seqs{$escseq}) {
        $seqs{$escseq}->();   # call associated subroutine
        print "$n\n";
    }
}
ReadMode 0;  # reset tty
[download]