Is there an easy way to add it to a boostrap input?

[gaining]

For example, something like this
<input class="form-control" id="address" name="address">

[crudenorway]

You can do this: :)

let autocomplete = new GeocoderAutocomplete(element, "apikey", {
            /* Geocoder options */
});
autocomplete.inputElement.classList.add("form-control");

But there should be a way of defining custom classes in the geocoder options as well. Maybe in a future release?