Additionally...if the syntax is correct, could it be that you can't insert an mbox parameter and pull it back out in the same page? I figured I might be able to depending on the order of the calls (insert first, mbox fill, target audience check, target experience delivered - with custom mbox param i...

Here is the script...I'm injecting it via a tag management application and pushing it out before all other load rules:const queryString = window.location.search;const urlParams = new URLSearchParams(queryString);var MyParam = "";if (urlParams.has('TESTParam')) {MyParam= urlParams.get('TESTParam');ta...

I'm using targetPageParams to add a parameter into the mbox (default mbox), lets call it "MyParam". In my script its pulling in a querystring parameter and setting a custom mbox parameter to the value found there.Example URL: [my URL]?TESTParam=xyz123I know Target has seen  "MyParam" in the mbox bec...