jQuery Simple Example

HTML

<script src="//www.addressfinder.co.nz/assets/v2/widget.js"></script>
<label for="search_field">Address</label>
<input type='text' class='address_field' name="address" id="address" />

CSS

body {
    padding: 5px;
}

label {
    font-weight: bold;
}

input[type=text] {
    width: 20em
}

p {
    margin: 1em 0 0;
}

JavaScript

function makeid()
    {
        var text = "";
        var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        for( var i=0; i < 8; i++ )
            text += possible.charAt(Math.floor(Math.random() * possible.length));
        return text;
    }

    var urlParams = new URLSearchParams(window.location.search);
    var keys = urlParams.keys();
    for (key of keys) {}
    setTimeout(function() {
      if(document.location.search.length) {
      } else {
        $('#address').val(makeid());
      }
    }, 3000);