How to create custom “Duplicate” buttons for Adminhtml Edit Form save custom module in Magento2.1 and save and saveandcontinue Functionally not change.

Now duplicate button already create and onclick use setLocation but i have from submit so please any idea how to use button event in magento 2.1

```
        $this->buttonList->add(
            'duplicate',
            [
                'class' => 'save',
                'label' => __('Duplicate'),
                'onclick' => 'setLocation("' . $duplicateUrl . '")'
            ],
            12 // sort order
        );

```