Photos option not appearing in icloud settings (Mac)

Hi,

I am trying to clear space on my 2017 intel MacBook Pro (running Sierra). I do have a lot of photos tied to my icloud account (astonishingly around 1.5TB), which is taking up 64GB on this Mac.

I wanted to disable the option for icloud syncing so that I can clear this off my Mac.

I have read that there should be an option under system preferences > icloud > photos, however I am not seeing photos under this directory. I do not have enough space on my Mac to update to a newer OS.

Is there a potential reason for this/a workaround for clearing this space?

Can confirm that the logged in user has admin privileges- I'm not aware of any group restrictions for this user.

Many thanks.