Creating creatures with constant spells

[mototom]

I'm trying to set up some of the creatures in The Slithering. Some have innate spells, and some of those are constant or at will.

How do you add spells to an NPC/monster that are constant or at will? I can only seem to add them as 1/day. I don't even see a way to set an innate spell to multiple times per day.