Cannot upload photos or videos to Facebook or Instagram from my MacBook Air

Whenever I try to select upload photo (or video) whilst in Facebook or Instagram when using my MacBook Air, nothing happens. It works perfectly well from my iPhone & my iPad but not my MacBook Air. I tried to follow the recommended steps which was to go to Settings - Privacy & Settings - Photos & ensure Facebook & Instagram were switched on but they don't even appear there & there is no option to add them. I am at a loss & it is truly annoying as I regularly create content for both accounts & switching to my mobile device from my laptop is annoying. I have attached a screenshot of my Privacy & Settings for Photos from my MacBook Air.

Any suggestions how to fix this?