Magento 2 - Call phtml in helper

I have figured out the solution. Copied from gift-card module (Enterprise)

For variables in constructor

protected $_layout;

public function __construct(
    ...
    \Magento\Framework\View\LayoutInterface $layout
    ...
) {
    $this->_layout = $layout;
    ...
}

Now in any of the function where you want to call phtml, use this:

$block = $this->_layout->createBlock(\Vendor\Module\Block\Index::class);
$block->setTemplate("Vendor_Module::index.phtml");
return $block;

You can use this:

$block = $this->_layout->createBlock(\Vendor\Module\Block\Index::class);
$block->setTemplate("Vendor_Module::index.phtml");
return $block;

Where $this->_layout is the instance of \Magento\Framework\View\LayoutInterface