Saving photos to iCloud
I pay for 2TB of icloud storage. My phone is 64GB. I have 35000 photos. My phone storage is at capacity, but I don't understand why the photos don't save to the iCloud drive instead of the phone. I've done the usual, go to icloud and sync photos, but it says only 2GB is taken up there, where 20GB is taken up on the phone itself.
Any advice?
Thanks
iPhone X, iOS 16