Synching photos on all devices via iCloud
Photos from my 3 devices (iPad, iPhone and MacBook) are all back up to iCloud, I believe..... settings as follows: >appleID>iCloud>Apps using iCloud: Photos.
I want all devices to synch with iCloud so that all photos taken on any device are automatically displayed in the Photos app on the other devices.
On both iPad and iPhone, when I select: >Settings>Photos>iCloud Devices - ON, i get the following message:
'Photos synched from Finder will be removed. Synching photos via Finder is not supported when iCloud Photos is turned on. 8124 photos will be removed''.
If I have recent backup of photos to iCloud on each device (as at today), will all photos currently on each device be in the cloud already, and does it just remove the photos off the memory of both the iPad/iPhone devices?
I really do not want to lose any photos, but need them too to synch between all 3 devices in future (all logged in to iCloud with the same apple ID.
Any help would be great - thanks
Sue
iPhone 13 Pro