取得したJSONデータへのアクセス方法を知りたい

前提

TwitterAPIを使用してRTした人を取得しようとしています。
JSONデータは取得できたのですがそのデータを扱おうとするとエラーになります。

該当ツイート：https://twitter.com/TwitterJP/status/1512360290192883712

【エラーメッセージ】
json[i][screenName]の中身は・・
<INVALID JSON>

該当のソースコード

Swift
1for i in 0..<json.array!.count {
2                     let retweeters = Tweeters(name: json[i]["name"].string ?? "ユーザーネームはありません", screenName: json[i]["screen_name"].string ?? "スクリーンネームはありません", profile_image_url: json[i]["profile_image_url"].string ?? "no_image")
3                     print("json[i][screen_name]の中身は・・")
4                     print(json[i]["screen_name"])
5}
6                
7

jsonの中身は・・
[
  {
    "in_reply_to_user_id_str" : null,
    "retweeted_status" : {
      "retweet_count" : 120.0,
      "in_reply_to_user_id_str" : null,
      "in_reply_to_screen_name" : null,
      "favorited" : false,
      "in_reply_to_status_id" : null,
      "favorite_count" : 613.0,
      "id" : 1.5123602901928837e+18,
      "retweeted" : false,
      "id_str" : "1512360290192883712",
      "text" : "金曜日よ、多くの人が君を待っていたぞ",
      "lang" : "ja",
      "coordinates" : null,
      "geo" : null,
      "contributors" : null,
      "entities" : {
        "user_mentions" : [

        ],
        "hashtags" : [

        ],
        "symbols" : [

        ],
        "urls" : [

        ]
      },
      "is_quote_status" : false,
      "truncated" : false,
      "source" : "<a href=\"http://twitter.com/download/iphone\" rel=\"nofollow\">Twitter for iPhone</a>",
      "in_reply_to_status_id_str" : null,
      "created_at" : "Fri Apr 08 09:22:46 +0000 2022",
      "in_reply_to_user_id" : null,
      "place" : null,
      "user" : {
        "profile_background_image_url_https" : "https://abs.twimg.com/images/themes/theme1/bg.png",
        "profile_sidebar_border_color" : "FFFFFF",
        "profile_sidebar_fill_color" : "DDEEF6",
        "id" : 7080152.0,
        "profile_link_color" : "1B95E0",
        "profile_image_url_https" : "https://pbs.twimg.com/profile_images/1354485696392613893/9T6ogVOI_normal.jpg",
        "lang" : null,
        "favourites_count" : 1049.0,
        "friends_count" : 108.0,
        "profile_background_color" : "C0DEED",
        "default_profile" : false,
        "entities" : {
          "url" : {
            "urls" : [
              {
                "display_url" : "blog.twitter.com/ja_jp.html",
                "url" : "https://t.co/IgW6OEkIbG",
                "expanded_url" : "https://blog.twitter.com/ja_jp.html",
                "indices" : [
                  0.0,
                  23.0
                ]
              }
            ]
          },
          "description" : {
            "urls" : [

            ]
          }
        },
        "location" : "東京都中央区",
        "protected" : false,
        "name" : "Twitter Japan",
        "url" : "https://t.co/IgW6OEkIbG",
        "id_str" : "7080152",
        "geo_enabled" : true,
        "statuses_count" : 14635.0,
        "description" : "What is Happening?! 今日も何かが起きている?!",
        "is_translator" : false,
        "profile_text_color" : "333333",
        "notifications" : false,
        "time_zone" : null,
        "profile_use_background_image" : true,
        "profile_banner_url" : "https://pbs.twimg.com/profile_banners/7080152/1647824977",
        "followers_count" : 2283978.0,
        "profile_image_url" : "http://pbs.twimg.com/profile_images/1354485696392613893/9T6ogVOI_normal.jpg",
        "verified" : true,
        "profile_background_image_url" : "http://abs.twimg.com/images/themes/theme1/bg.png",
        "following" : false,
        "translator_type" : "regular",
        "profile_background_tile" : true,
        "is_translation_enabled" : false,
        "listed_count" : 14847.0,
        "contributors_enabled" : false,
        "screen_name" : "TwitterJP",
        "utc_offset" : null,
        "default_profile_image" : false,
        "created_at" : "Tue Jun 26 01:54:35 +0000 2007",
        "has_extended_profile" : true,
        "withheld_in_countries" : [

        ],
        "follow_request_sent" : false
      }
    },
    "in_reply_to_screen_name" : null,
    "is_quote_status" : false,
    "user" : {
      "profile_link_color" : "1DA1F2",
      "is_translation_enabled" : false,
      "followers_count" : 502.0,
      "contributors_enabled" : false,
      "geo_enabled" : false,
      "has_extended_profile" : true,
      "lang" : null,
      "description" : "",
      "profile_background_image_url_https" : null,
      "created_at" : "Tue Jun 22 06:37:40 +0000 2021",
      "withheld_in_countries" : [

      ],
      "default_profile" : true,
      "following" : false,
      "is_translator" : false,
      "time_zone" : null,
      "verified" : false,
      "profile_text_color" : "333333",
      "default_profile_image" : false,
      "id" : 1.407226176892932e+18,
      "listed_count" : 0.0,
      "favourites_count" : 15669.0,
      "entities" : {
        "description" : {
          "urls" : [

          ]
        }
      },
      "profile_background_tile" : false,
      "notifications" : false,
      "name" : "mau 🐌 ia",
      "statuses_count" : 22481.0,
      "protected" : false,
      "friends_count" : 486.0,
      "profile_background_image_url" : null,
      "profile_use_background_image" : true,
      "profile_image_url_https" : "https://pbs.twimg.com/profile_images/1502988579290509314/vaqDinyV_normal.jpg",
      "profile_sidebar_border_color" : "C0DEED",
      "translator_type" : "none",
      "screen_name" : "cheolsauriki",
      "profile_banner_url" : "https://pbs.twimg.com/profile_banners/1407226176892932096/1648038723",
      "url" : null,
      "profile_background_color" : "F5F8FA",
      "follow_request_sent" : false,
      "profile_sidebar_fill_color" : "DDEEF6",
      "location" : " 💭 that prince from okayama | mainly 엔하                       \nany pronouns — selective ¡ sf to unf. ",
      "id_str" : "1407226176892932096",
      "profile_image_url" : "http://pbs.twimg.com/profile_images/1502988579290509314/vaqDinyV_normal.jpg",
      "utc_offset" : null
    },
    "favorited" : false,
    "place" : null,
    "created_at" : "Tue Apr 12 04:05:17 +0000 2022",
    "geo" : null,
    "coordinates" : null,
    "text" : "RT @TwitterJP: 金曜日よ、多くの人が君を待っていたぞ",
    "retweet_count" : 120.0,
    "in_reply_to_status_id" : null,
    "in_reply_to_status_id_str" : null,
    "source" : "<a href=\"http://twitter.com/download/android\" rel=\"nofollow\">Twitter for Android</a>",
    "id" : 1.5137299468162458e+18,
    "lang" : "ja",
    "retweeted" : false,
    "id_str" : "1513729946816245763",
    "in_reply_to_user_id" : null,
    "favorite_count" : 0.0,
    "contributors" : null,
    "entities" : {
      "symbols" : [

      ],
      "hashtags" : [

      ],
      "user_mentions" : [
        {
          "id" : 7080152.0,
          "id_str" : "7080152",
          "name" : "Twitter Japan",
          "indices" : [
            3.0,
            13.0
          ],
          "screen_name" : "TwitterJP"
        }
      ],
      "urls" : [

      ]
    },
    "truncated" : false
  }
]