I have the same problem. I want to download photos in .jpg format and after reading all the replies and it states you can export with different option. I only have the option to export as .pdf.
This really sucks why have a iCloud back up if I am unable to use it?
iMac 27" 5K, macOS 10.15
Have you tried this steps:
Download iCloud photos and videos
https://support.apple.com/en-us/HT209454
If you need help I suggest to contact Apple Support, they will be able to isolate the issue with you and help you completing the download.
P.S.: iCloud Backup is encrypted and not related to iCloud Photo Library
You can find more info about it here:
What does iCloud back up?
https://support.apple.com/en-hk/HT207428
Restore or set up your device from an iCloud backup
Set up and use iCloud Photos
Have you tried this steps:
Download iCloud photos and videos
https://support.apple.com/en-us/HT209454
If you need help I suggest to contact Apple Support, they will be able to isolate the issue with you and help you completing the download.
P.S.: iCloud Backup is encrypted and not related to iCloud Photo Library
You can find more info about it here:
What does iCloud back up?
https://support.apple.com/en-hk/HT207428
Restore or set up your device from an iCloud backup
Set up and use iCloud Photos
download iCloud photos to Mac
