You've edited your site and the JSON now looks like:

{
  "feeds": [
    {
      "subscribe_URL": "https:\/\/the-art-of-autism.com\/feed\/",
      "feed_ID": "34259929",
      "meta": {
        "links": {
          "feed": "https:\/\/public-api.wordpress.com\/rest\/v1\/read\
+/feed\/34259929",
          "site": "https:\/\/public-api.wordpress.com\/rest\/v1\/read\
+/sites\/57595012"
        }
      }
    },
    {
      "subscribe_URL": "https:\/\/the-art-of-autism.com\/sample-page-2
+\/feed\/",
      "feed_ID": "",
      "meta": {
        "links": {
          
        }
      }
    },
    {
      "subscribe_URL": "http:\/\/the-art-of-autism.com\/feed\/",
      "feed_ID": "34259929",
      "meta": {
        "links": {
          "feed": "https:\/\/public-api.wordpress.com\/rest\/v1\/read\
+/feed\/34259929",
          "site": "https:\/\/public-api.wordpress.com\/rest\/v1\/read\
+/sites\/57595012"
        }
      }
    }
  ]
}
[download]

Note Sample page 2 has no links. A fix for the code:

my $json = $ua->get( $url )->res->json; 
for my $feed ( @{$json->{feeds}} ){
  
  if ( $feed->{meta}{links}{feed} ){
    print "$feed->{meta}{links}{feed}\n";
  }
}
[download]

"which I couldn't figure out how to reply to directly" If viewing a node directly you'll see a link reading "Comment on {Node title here}", if viewing in thread mode you'll see a link titled "[reply]" at the bottom right of each reply.