Built-in scientific calculator enable/disable option

As of a month or so ago, the activity builder automatically prompted me to enable or disable a scientific calculator when I created activities. When enabled, the calculator button would appear at the top center of student’s screen, as shown in the image I’ve uploaded. But I’m no longer seeing an option for enabling/disabling the calculator. Anyone know about this?
Desmos Scientific Calculator|690x387

open the activity details menu:
image
Theres a checkbox at the bottom to enable the scientific calculator:

Thanks for the quick and helpful response!

I just added this to one of my lessons today!
I love that the calculator lets you save variables…