system photo library
I followed the instructions here (https://support.apple.com/kb/index?page=search&type=organic&src=support_searchbox_main&locale=en_US&q=system+photo+library) but when I open photos preference the option to "use as system photo library" is greyed out and can't be checked. iCloud is signed in on computer and turned on in iPhoto and I have just one photo library but it is not uploading the photos on phone, which is also signed into same iCloud. thanks!
MacBook, macOS 10.13