Repository: yt-dlp
Issue: Unsupported URL error for nationalgeographic.com
Labels: site-bug

### Checklist

- [X] I'm reporting a broken site
- [X] I've verified that I'm running yt-dlp version **2021.10.22**. ([update instructions](https://github.com/yt-dlp/yt-dlp#update))
- [X] I've checked that all provided URLs are alive and playable in a browser
- [X] I've checked that all URLs and arguments with special characters are [properly quoted or escaped](https://github.com/ytdl-org/youtube-dl#video-url-contains-an-ampersand-and-im-getting-some-strange-output-1-2839-or-v-is-not-recognized-as-an-internal-or-external-command)
- [X] I've searched the [bugtracker](https://github.com/yt-dlp/yt-dlp/issues?q=) for similar issues including closed ones. DO NOT post duplicates
- [X] I've read the [guidelines for opening an issue](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#opening-an-issue)
- [X] I've read about [sharing account credentials](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#are-you-willing-to-share-account-details-if-needed) and I'm willing to share it if required

### Region

United States

### Description

I am trying to pass a URL from nationalgeographic.com, but I am recieveing an Unsupported URL error.  The video will play just fine in my browser.  

Here is the URL in question:
https://www.nationalgeographic.com/tv/shows/the-incredible-dr-pol/episode-guide/season-19/episode-01-the-magic-touch/vdka23842525

### Verbose log

```shell
Microsoft Windows [Version 10.0.19042.1288]
(c) Microsoft Corporation. All rights reserved.

F:\Youtube>yt-dlp -Uv https://www.nationalgeographic.com/tv/shows/the-incredible-dr-pol/episode-guide/season-19/episode-01-the-magic-touch/vdka23842525

[debug] Command-line config: ['-Uv', 'https://www.nationalgeographic.com/tv/shows/the-incredible-dr-pol/episode-guide/season-19/episode-01-the-magic-touch/vdka23842525']
[debug] Encodings: locale cp1252, fs utf-8, out utf-8, err utf-8, pref cp1252[debug] yt-dlp version 2021.10.22 (win_exe)[debug] Python version 3.8.10 (CPython 64bit) - Windows-10-10.0.19042-SP0
[debug] exe versions: ffmpeg 2020-10-11-git-7ea4bcff7b-full_build-www.gyan.dev
[debug] Optional libraries: Cryptodome, mutagen, sqlite, websockets
[debug] Proxy map: {}
yt-dlp is up to date (2021.10.22)
[debug] [generic] Extracting URL: https://www.nationalgeographic.com/tv/shows/the-incredible-dr-pol/episode-guide/season-19/episode-01-the-magic-touch/vdka23842525
[generic] vdka23842525: Requesting header
WARNING: [generic] Falling back on generic information extractor.
[generic] vdka23842525: Downloading webpage
[generic] vdka23842525: Extracting information
ERROR: [generic] Unsupported URL: https://www.nationalgeographic.com/tv/shows/the-incredible-dr-pol/episode-guide/season-19/episode-01-the-magic-touch/vdka23842525
Traceback (most recent call last):
  File "yt_dlp\extractor\common.py", line 593, in extract
  File "yt_dlp\extractor\generic.py", line 3706, in _real_extract
yt_dlp.utils.UnsupportedError: Unsupported URL: https://www.nationalgeographic.com/tv/shows/the-incredible-dr-pol/episode-guide/season-19/episode-01-the-magic-touch/vdka23842525
Traceback (most recent call last):
  File "yt_dlp\extractor\common.py", line 593, in extract
  File "yt_dlp\extractor\generic.py", line 3706, in _real_extract
yt_dlp.utils.UnsupportedError: Unsupported URL: https://www.nationalgeographic.com/tv/shows/the-incredible-dr-pol/episode-guide/season-19/episode-01-the-magic-touch/vdka23842525

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "yt_dlp\YoutubeDL.py", line 1280, in wrapper
  File "yt_dlp\YoutubeDL.py", line 1305, in __extract_info
  File "yt_dlp\extractor\common.py", line 609, in extract
yt_dlp.utils.ExtractorError: [generic] Unsupported URL: https://www.nationalgeographic.com/tv/shows/the-incredible-dr-pol/episode-guide/season-19/episode-01-the-magic-touch/vdka23842525


F:\Youtube>
```