Your password is required to enable iCloud photo library
After I open Apple ID in my system preferences how do I turn on the iCloud photo library?
Question marked as
Top-ranking reply
There are 2 places you need to go to for iCloud Photos to be enabled.
Open system preferences, click on Apple ID at the top and make sure the Photos box is ticked.
Then go to the Photos app, open preferences, select 'Use as system Library' under the first tab and then open the second tab and select iCloud Photos.