How to stop Synology Photos from backing up my entire library again

[Anbo]

My iPhone recently died and I have just bought a new replacement. I had Synology Photos on the old one backing up my photos taken on the phone. That worked well. However, since getting the new phone and restoring it from iCloud, Synology Photos it trying to backup my entire photo library again.
Does anyone know how I can get it to just start backing up the new photos I take from now on and disregard the ones that have already been backed up from the old phone?

 

[fredbert]

I can't see it on my iPhone, I've already got backup configured, but I was sure that when setting it up you had the option for all photos/videos or only new ones from now.

It's hard to remember since there are three mobile apps that all offer camera roll backup: Photos Mobile; Synology Drive; DS file.

 

[Anbo]

Actually, I just found the setting you mentioned.