How To Get Bootstrap Dropdown?

Sorry for the basic question. But I cannot find out how to get a Bootstrap Dropdown.

In my view I think I need something like


<?= \yii\bootstrap\Dropdown::widget([...]) ?>

But what are the arguments? How can I populate it?

And also I need to have something like ‘onchange’=>‘this.form.submit()’ since I have to show different input fields when the user has selected a dropdown item. How can I do this? Same way as with Html::dropDownList()?

Could anyone provide an example?

Thanks.