how do i randomly pick something from an array and set it to a variable for PlayerInteractEvent

I'm trying to make a cratekey plugin and I need to know how to randomly get something from an array and set it to a variable and it will become a variable every time someone touches the crate so its random

 

PHP:

$stuff = ["Juice", "dktapps", "shoghicp"];
$randomstuff = $stuff[array_rand($stuff)];


The event for touching blocks is PlayerInteractEvent, there are many resources to find out how to use it