Photos won't sync with iCloud

again

iPhoto has no capability to sync with iCloud Photo Library - what devices do you have and what are he icCoud settings on each and the OS/IOS version on each? What is the iCloud Photo library status on your Mac? Check the status of your library in Photos for macOS - Apple Support

You did not answer a single question -- and what version of iPhoto are you using and with what OS?

it is not possible to assist you unless you provide requested information

LN

Only one of your libraries can sync with iCloud services on your Mac. If My Photo Stream is enabled for your iPhoto Library, you cannot use it for your Photos Library as well. And if you switch My Photo Stream from iPhoto to your current System Photos Library in Photos, you will no longer be able to use My Photo Stream and shared albums in iPhoto. You have to make up your mind, if you want to stream the photos with My Photo Stream to your iPhoto Library or your Photos Library.

again iPhoto has no ability to sync with iCloud - MyPhotoStream is not a sync service (it is a one time streaming service and no changes are streamed) and it is not visible on iCLoud.com - Photos can sync with iCloud Photo Library (which is what you see on iCloud.com), iPhoto can not

LN

this is confusing as iPhoto has no capability to sync with iCloud Photo Library - what devices do you have and what are he icCoud settings on each and the OS/IOS version on each? What is the iCloud Photo library status on your Mac? Check the status of your library in Photos for macOS - Apple Support

LN