Use case: Ecosystem partner application and PetHub widget reside on the same page.
The following script would also need to be included after the iFrame code:
<script>
var iframe = document.getElementById('pbph-widget')
if(typeof(iframe) != 'undefined' && iframe != null) {
var url = iframe.src
var addQueryParam = url?key1="+{value1}"
iframe.src= addQueryParam
}
</script>