I can’t find availability yet for my dates, but that’s another story.
https://disneyworld.disney.go.com/dining/magic-kingdom/jungle-navigation-skipper-canteen/
Darn, got ahead of myself, sorry. It looks like you can make ADRs in advance, but you can’t yet. I tried to delete my post, but it won’t let me, so I changed the title.
Someone just posted on chat that they were accepting same-day reservations as of today.