Centre flux in container F3

I’ve put a flux stack into a container (set to div) with max width 800 pixels, but can’t seem to be able to centre the flux contents.
The page is set up with Partitions track.

Attaching screenshot which shows flux positioned to the left of the container.
Any help would be appreciated

I’d need to see your particular layout to help further. That said you’d need to design your Flux grid layout to account for the “centering” of the content. Have a deeper look at your design.