I cloud
I don’t have enough storage on my phone. I’ve backed up my photos on the cloud and now I want to delete them on my phone but it tells me if I do that it will delete them from my cloud as well
Question marked as
If you turned on "iCloud Photos" that is not the same as iCloud Backup. Indeed you cannot back them up to iCloud Backup.
iCloud Photos is a sync to all devices feature. If you want to save space use the Optimise Storage feature in Settings, General, iPhone Storage.
Or download/import all your Photos to a computer and sync some or all of them back to the phone from there.