I tried some ways to be able to interact with the iframe but cannot add js to iframe

My code use iframe with the source:

<div class='roomle-configurator--wrapper'>
    <iframe id="frRoomle" src="https://www.roomle.com/t/cp/?configuratorId=delife&id=delife:product_test_1&api=false" width="1024" height="768"></iframe>
</div>

I use the below code but it doesn't work, I think the issue is caused blocking by src https://www.roomle.com

var script = "alert('hello world');";
$('#frRoomle').contents().find('body').append($('<script>').html(script))