Add Custom Button in the Admin Product Form in Magento 2

The product form is generated via UI-Components. If we need to add a custom button in admin product form, then it can be possible by the following way.

The UI component name for the product form is :

view/adminhtml/ui_component/product_form.xml.

You need to create a file with the same name and path in your own module with the following content:

<?xml version="1.0" encoding="UTF-8"?>
<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
   <!--For custom button-->
   <argument name="data" xsi:type="array">
       <item name="buttons" xsi:type="array">
           <item name="customButton" xsi:type="string">Webkul\CustomButton\Block\Adminhtml\Product\CustomButton</item>
       </item>
   </argument>
</form>

2. Then create the class in the file

Vendor/Module/Block/Adminhtml/Product/CustomButton.php

<?php
namespace Webkul\CustomButton\Block\Adminhtml\Product;
class CustomButton extends \Magento\Catalog\Block\Adminhtml\Product\Edit\Button\Generic
{
    public function getButtonData()
    {
    	return [
        	'label' => __('Custom Button'),
        	'class' => 'action-secondary',
        	'on_click' => 'alert("Hello Webkul !!")',
        	'sort_order' => 10
    	];
    }
}

Then, Just flush the Cache and your UI-Component file will merge with the main file and your button will appear among the other buttons.