Totally agree with The Garden Baker…piping gel. I have used edible glue too, but it dries very quickly, and sprinkles don’t always stick right away. That’s a pain. Wait until you’re fondant once painted, is very firm and hard. Then as advised have a tray underneath to catch the sprinkles as you attach. I wouldn’t paint on the cake when the fondant is soft, possibility the colour with alcohol will soak into the soft fondant. Then you will have to reapply. You want your fondant firm anyway so you can use your smoothers and get clean, crisp sides and top on your cake. Make sure your colours are food safe. I use food grade paint brushes, strictly for cake decorating.
Creativity is God's gift to us. Using our creativity is our gift back to God. Clarky's Cakes 😎