#use Encode; # used previously
use LWP::UserAgent;

my $ua = LWP::UserAgent->new();

my $URL = 'https://public-api.wordpress.com/rest/v1/read/feed/http%3A%2F%2Fthe-art-of-autism.com%2Ffeed';
my $response = $ua->get($URL);

die $response->status_line unless $response->is_success;

my $contents = Encode::encode 'UTF-8', $response->decoded_content;

...