How do I make a skript that gives you a shulker box containing items when you do a command?

[someinnocentman]

This is what I've got so far

command /supplycratesphinx:
    permission: sphinx.crate
    trigger:
    give {sphinxcrate} to player

I used !set {sphinxcrate} to tool to set the variable

 

[Comet]

What is the error?

 

[someinnocentman]

What is the error?

Sorry for the late reply, there's no error. It just doesn't give me the shulker at all