Convert html to json in php laravel

Im hitting this url

https://graph.facebook.com/1843624489016097?fields=link&access_token=EAAD3ZBKkIhYMBAL3KRi9eZBXlYJADZARRFMSe0Nc35WTP92X2etkccVqnjNcjJgKbd8ABtX5pyDPN0nAA7jORyjpOGexZCYp1Sf2iw0DJjCf8UkPiLwhuApSGDGZBvy5w7vk3U0Ba97FZA2DO7J4m4UjvbIolDaRP9TRpemEmLyQZDZD

with the below code in php,

$url ='https://graph.facebook.com/' . $connection->provider_id . '?fields=link&access_token=' . $connection->token;
$ch = curl_init($url);
$json= curl_exec ($ch);

I have this html coming from Facebook, I want to use only "Link" in this,

{"link":"https:\/\/www.facebook.com\/app_scoped_user_id\/YXNpZADpBWEdrUlJiUzc0SWFWZATI4SEVJUmJHTTJQVHU2M3owcTJLOHh5MnJYOTI0LWdMT3VFUC1veXNWdXBhM3o3RzdkQmV4cjNfTC1nSkdheGFhV19pWWU5T1ZAWSzlkN0NBTUl4NVZAKTE9oRjlFbjdObU5i\/","id":"1686741234967769"}1

I tried converting that into JSON but its not working, Its coming in same format, since im doing this in a API, im checking this under Postman, I did like this..

$request = json_encode($json, JSON_HEX_QUOT | JSON_HEX_TAG);

The format is not getting convert to json, Im doing in PHP Laravel.

via Chebli Mohamed