#!/usr/bin/perl

use strict;
use warnings;
use 5.018;
use utf8;

use LWP::UserAgent;

my $url = 'https://www.youtube.com/channel/UC5YPvina0jntpfIkiHNIi6w';

my $ua = LWP::UserAgent->new();
$ua->agent('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.75 Safari/537.36');
my $res     = $ua->get($url);
my $content = $res->content;

# Zu uniq von Array-Werten siehe https://perlmaven.com/unique-values-in-an-array-in-perl
my @unique = do {
  my %seen;
  grep { 
    !$seen{$_}++ 
  } 
  $content =~ m|"videoId":"([^"]+)"|g;
  # Ids in JSON "videoId":"Du8OyyaOgN4"
};