How to scrape images from a flickr group?

Recently for a project I have to create a scraper that can download all the pictures in a group pool. Unfortunately, I am not sure how to do this since all the pictures are by different users and none of the pictures specifically end with .jpg or .png, etc.

I have tried to use someone's github code, linked here, and the error

Traceback (most recent call last):
  File "flickr_scraper.py", line 83, in <module>
    main()
  File "flickr_scraper.py", line 73, in main
    for i, photo in enumerate(photos):
  File "flickr_scraper.py", line 37, in get_photos_for_person
    pages = get_flickr_page(nsid)['photos']['pages']
KeyError: 'photos'

I would greatly appreciate if someone could provide code, or atleast point me in the right direction, I already have a flickr API key.