How to add dropdown to product variation in grid.phtml

I want add variation dropdown instead of multiple div swatch option. I am not getting how to do in grid.phtml.

Below is the code swatch option display

<?= $block->getProductPriceHtml($_item, $type) ?>
<div class="pro-weight">
<?php if ($_item->isSaleable()): ?>
<?php $postParams = $block->getAddToCartPostParams($_item); ?>
<?php echo $block->getProductDetailsHtml($_item); ?>
<?php endif; ?>
</div>

but i want as dropdown for multiple variation else just text in div