Realm Http Service IP Rule


I’m trying to restrict access to a n HTTP Service Enpoint and don’t know how to build the correct
JSO expression. I see something in the docs with an example similar to:

    "" : {
        "%in" :[ "",""]

This does not work.

I also don’t know what args are in the expression. Are they arguments to the function?
In which case, I’ve tried

    "%%args.payload.headers.Origin" : {
        "%in" :[ "","", "", ""]

And get the following error:

“incoming webhook evaluation blocked by CanEvaluate”

Anyone know how to do this?