WC product loop title to h2

functions.php

if ( ! function_exists( 'dt_woocommerce_template_loop_product_title' ) ) :

	/**
	 * Show the product title in the product loop.
	 */
	function dt_woocommerce_template_loop_product_title() {
		if ( presscore_config()->get( 'show_titles' ) && get_the_title() ) : ?>
			<h2 class="entry-title">
				<a href="<?php the_permalink(); ?>" title="<?php echo the_title_attribute( 'echo=0' ); ?>" rel="bookmark"><?php
					the_title();
				?></a>
			</h2>
		<?php endif;
	}

endif;

Please try this code in your child theme functions.php