Dancing Monkey Fruit effect script

I'm still learning the ropes of how to write effects. I figured out how to apply the conditions for consuming dancing monkey fruit from Tomb of Annihilation (DISATK; DISSAV: dexterity; GRANTADVATK), but I cannot figure out how to trigger the DC 14 constitution saving throw if damage is taken. Do I nest the entire effect in an IF (SAVE: constitution 14) or is there a natural language statement I should be using? Also, what's the syntax for if damage is taken? I looked through the wiki and I couldn't figure out answers to either of these questions. Any help would be appreciated!

Here's the text of the item:
DANCING MONKEY FRUIT
This rare magical fruit produces enough juice to fill a vial. Any humanoid that eats a dancing monkey fruit or drinks its juice must succeed on a DC 14 Constitution saving throw or begin a comic dance that lasts for 1 minute. Humanoids that can't be poisoned are immune to this magical effect.

The dancer must use all its movement to dance without leaving its space and has disadvantage on attack rolls and Dexterity saving throws, and other creatures have advantage on attack rolls against it. Each time it takes damage, the dancer can repeat the saving throw, ending the effect on itself on a success. When the dancing effect ends, the humanoid suffers the poisoned condition for 1 hour.

There is no effect or method which will automatically force a saving throw. You could create an NPC for the monkey juice (assuming I didn’t create one in the module - I can’t remember) and with the correct wording it will create a save on the CT which can be dropped on the PC when needed.

There’s also no effect or wording which detects damage.

Thanks! That's kind of what a figured. Some of Rob Twohy's mods force a concentration check when hit and I figured that involved lua programming, but hoped it used the ruleset scripts. I'll check more closely to see if the module is structured with an NPC to create the effect. If not, I'll just add the saves as text to the effect and leave it to the player to check (just like IRL). If they forget it's on them :)

Concentration is built into the ruleset. All you need is to add a ;(C) to the end of the effect to make it a concentration effect. FG will automatically make the concentration roll on taking damage. So, yes, that is scripted and isn’t an effect.

Also if I added that as a magic item then I probably didn’t add it as an NPC. If it was a trap or hazard then I normally would add it as an NPC.