workaround

main.py

@@ -37,6 +37,7 @@ async def check_updates():
                       f'Artist: {" ".join(post.tags.artist)}\n' \
                       f'Character: {" ".join(post.tags.character)}\n\n' \
                       f'https://e621.net/posts/{post.id}'
+            if post.file.url:
                 if post.file.ext == 'webm':
                     await bot.send_video(int(os.environ['SEND_CHAT']),
                                          post.file.url,