The preferred way to install this extension is through composer.
Either run
php composer.phar require --prefer-dist rustamwin/yii2-checkbo "*"
or add
"rustamwin/yii2-checkbo": "*"
to the require section of your composer.json file.
<?= $form->field($model, $attribute)->widget(CheckBo::class, []) ?>yii2-checkbo is released under the MIT License.