how to use url parameters in html?

I get URL parameters using Javascript but i can't use those variables in my html. the JS code is this:

<script>
var url_string = window.location.href; //window.location.href
var url = new URL(url_string);
var c = url.searchParams.get("name");
console.log(c);
</script>

and my URL is localhost:8000/something?name=ABC.here i can get the value of name and show it in the browser console but when i try to set the value of an input tag in my HTML it doesn't do it and raises some errors. my JS and html is like:

<script>
    var url_string = window.location.href; //window.location.href
    var url = new URL(url_string);
    var c = url.searchParams.get("name");
    document.getElementById("user").value =url.searchParams.get("name");
    </script>
<input id="user" value"">

this should have changed the value of the input tag but doesn't.