The preferred way to install this extension is through composer.
Either run
php composer.phar require muhiddin/yii2-multiple-select "dev-master"
or add
"muhiddin/yii2-multiple-select": "dev-master"
to the require section of your composer.json file.
echo $form->field($model, 'attribute')->widget(\muhiddin\select\MultiSelect::className(), [
'data' => $dataList,
'id' => 'multiple-select',
'options' => [
'multiple' => 'multiple',
],
'selectAll' => true,
'deselectAll'=>true,
])
```