script Changing an Init script to a trigger?

[PhallusLad 0]

Hey there guys, so I'm pretty new to scripting and I've ran into something I could do with a little help with. I'm trying to use this script
 

To make loot spawn in a crate, but I don't need it to be done on the missions init, I need it to be based on a repeatable trigger so it only activates when a player gets close to it.

Is there a way to do this?