API - File Attachment Download - Resource not found

Yes.  In the end this works for me.

#Get image url using your method of choice

import urllib.request
from PIL import Image
from io import BytesIO

url = urllib.request.urlopen('https://the_image_url?usertoken=' + quickbase_token)
s = url.read()

img = Image.open(BytesIO(s))

img.show() #or do whatever you want with it