Google Photos album does not work if you don't sync your photos.

My girlfriend has an iPhone and syncs her photos on iCloud. I ask her to create an album in Google photos and send me the invite. But it never works, I don't get an invite at all. It worked once a while ago and I'm almost sure the reason was because she had turned on the synchronization. If that's the case it shouldn't be an option to create and share the album, it just hurts)?)