更改iframe内的标签

Question

我的网上有一个iframe，但标签是英文的，所以我想用JavaScript改成法语 iframe是

<iframe src="https://nacampaigndirector.myconnectwise.net/serv/form/584188297a3e9a6447c4d307/58ee7ab77a3e9a22fc1d978c" scrolling="no" width="650px" height="600px" frameborder="0"></iframe>

我的代码是javascript是

<script>
var x = document.querySelectorAll(".col-sm-4 .control-label .ng-binding .fb-required");

x[0].innerHTML = "companies";
x[1].innerHTML = "Nom";
x[2].innerHTML = "Prenom";
x[3].innerHTML = "Telephone";
x[4].innerHTML = "Courriel";

</script>

但是没有使用我的代码