Dropdown grouped products woocommerce

In <thememap>/woocommerce/single-product/add-to-cart/grouped.php

<?php
/**
 * Grouped product add to cart
 *
 * This template can be overridden by copying it to yourtheme/woocommerce/single-product/add-to-cart/grouped.php.
 *
 * HOWEVER, on occasion WooCommerce will need to update template files and you
 * (the theme developer) will need to copy the new files to your theme to
 * maintain compatibility. We try to do this as little as possible, but it does
 * happen. When this occurs the version of the template file will be bumped and
 * the readme will list any important changes.
 *
 * @see     https://docs.woocommerce.com/document/template-structure/
 * @package WooCommerce\Templates
 * @version 4.8.0
 */

defined( 'ABSPATH' ) || exit;

global $product, $post;

do_action( 'woocommerce_before_add_to_cart_form' ); ?>

<form class="cart grouped_form" action="<?php echo esc_url( apply_filters( 'woocommerce_add_to_cart_form_action', $product->get_permalink() ) ); ?>" method="post" enctype='multipart/form-data'>
			<?php
			$quantites_required      = false;
			$previous_post           = $post;
			$grouped_product_columns = apply_filters(
				'woocommerce_grouped_product_columns',
				array(
					'quantity',
					'label',
					'price',
				),
				$product
			);
			$options = '';
			$show_add_to_cart_button = false;

			do_action( 'woocommerce_grouped_product_list_before', $grouped_product_columns, $quantites_required, $product );

			foreach ( $grouped_products as $grouped_product_child ) {
				$post_object        = get_post( $grouped_product_child->get_id() );
				$quantites_required = $quantites_required || ( $grouped_product_child->is_purchasable() && ! $grouped_product_child->has_options() );
				$post               = $post_object; // phpcs:ignore WordPress.WP.GlobalVariablesOverride.Prohibited
				setup_postdata( $post );

				if ( $grouped_product_child->is_in_stock() ) {
					$show_add_to_cart_button = true;
				}
				$options .= '<option value="' . $grouped_product_child->get_id() . '">' . $grouped_product_child->get_name(). '</option>';
				
			}
			$post = $previous_post; // phpcs:ignore WordPress.WP.GlobalVariablesOverride.Prohibited
			setup_postdata( $post );

			do_action( 'woocommerce_grouped_product_list_after', $grouped_product_columns, $quantites_required, $product );
			?>

	 <?php
	   echo '<select class="multi-prod form-select mb-1">'.$options.'</select>';
	   $post = $previous_post; // WPCS: override ok.
	   setup_postdata( $post );
	   ?>
	  <script>
	  jQuery('.multi-prod').change(function(e){
		$this = $(this)
		jQuery('.qty').attr('value', $this.val())
	  })
	  </script>
	
	<input type="hidden" class="input-text qty text" name="add-to-cart" value="" />

	<?php if ( $quantites_required && $show_add_to_cart_button ) : ?>

		<?php do_action( 'woocommerce_before_add_to_cart_button' ); ?>

		<button type="submit" class="single_add_to_cart_button btn btn-primary alt"><?php echo esc_html( $product->single_add_to_cart_text() ); ?></button>

		<?php do_action( 'woocommerce_after_add_to_cart_button' ); ?>

	<?php endif; ?>
</form>

<?php do_action( 'woocommerce_after_add_to_cart_form' ); ?>

#add to cart #grouped #product #woocommerce