disable fall damage until hit

https://cdn.discordapp.com/attachments/1332201865559019711/1334952227349074011/20250131-1823-04.6404758.mp4?ex=679e66a5&is=679d1525&hm=b98154dc19adb43c7d009fdad994fef2812e3e992209264955be307a500536d2& is there something I can track via objective or something else for when the player touches the ground so I can detect when to disable immunity to fall damage and how can I give out the immunity to fall damage