@Html.AutoCompleteFor(model => model.Id, new PeopleDatalist())

@Html.DatalistFor(model => model.Id, new PeopleDatalist())

document.querySelector('button').addEventListener('click', function() {
    var element = document.getElementById('Id');
    var triggerChanges = true;

    element.value = parseInt(Math.random() * 20) + 1;
    new MvcDatalist(element).reload(triggerChanges);
});