Need to add storefront Canada to my campaign

Hey,

I am successfully running Advanced ad campaign in US, and I would like to extend the same for Canada. But In storefront i see only USA, but there is no option to edit that, its saying in suggestion to edit the storefront to run campaign in oethr countries but I am not finding any place where I can do that.

I spent so much time in figuring out this on my own but no luck, somebody please let me know how can I duplcate current campaign and run it in different region.

Thanks,

Sam