Can't add enclosure to atom correctly

[BlackLotus]

I'm probably doing something horribly wrong here, but if I generate an rss feed I can add enclosures with this code without any problems

fe.enclosure(url=original_image_url, length='0', type=f"image/{imgtype}")
fe.enclosure(url=proxy_image_url, length='0', type=f"image/{imgtype}")

When I generate the feed as rss

    rss_feed = fg.rss_str(pretty=True)                                                                                                                         

the last enclosure is shown as attachment/enclosure which is what I expected when I create an atom feed

    atom_feed = fg.atom_str(pretty=True)

I just get multiple link objects without any reference of them being an enclosure.
Here is example code to reproduce this behaviour

from feedgen.feed import FeedGenerator

fg = FeedGenerator()
fg.load_extension('podcast')

# Set required fields using the appropriate methods
fg.id('bla')
fg.title('a')
fg.link({'href': 'http://ponyhof.de'})  # Pass a dictionary with 'href' key
fg.description('http://ponyhof.de')
fg.podcast.itunes_category('Technology', 'Podcasting')

fe = fg.add_entry()
fe.id('http://lernfunk.de/media/654321/1/file.mp3')
fe.title('The First Episode')
fe.description('Enjoy our first episode.')
fe.enclosure('http://lernfunk.de/media/654321/1/file.mp3', 0, 'audio/mpeg')
fe.enclosure('http://lernfunk.de/media/654321/2/file.mp3', 0, 'audio/mpeg')

# Generate the RSS feed
rss_feed = fg.rss_str(pretty=True)
print(rss_feed)  # Optional: print the RSS feed to the console
fg.rss_file('podcast-rss.xml')
fg.atom_file('podcast-atom.xml')

Here is your documentation specifying that it should work https://python-feedgen.readthedocs.io/en/latest/api.entry.html#feedgen.entry.FeedEntry.enclosure
Here is the atom rfc specifying how it should look https://validator.w3.org/feed/docs/rfc4287.html

    <link rel="enclosure" type="audio/mpeg" length="1337"
     href="http://example.org/audio/ph34r_my_podcast.mp3"/>

please tell me I'm doing something wrong