<!–nextpage–> tag not showing up!

I have a problem with my “<!–nextpage–>” tag not showing up. Im using it to have multiple pages within an actual “Page” on my site. It cuts off where I want it to but it doesnt give a “pages: 1,2” link anywhere.

Im wondering if my theme supports it…but I thought all themes should

my site: https://ivybetty.com/?page_id=29

any help would be greatly appreciated.