ZSH's way to bind function to a key in a script?

[nix@xxxxxxxxxxxxxxxx]

Hi everyone. I was reading last night about "bindkey" etc. , and i could
not get it working.

#!/bin/zsh

function foo () {

echo "Foo ooo"
}

In this script, how to bind function "foo" to a key. So lets say i press
the Space button and it should trigger foo?