Change number of products per page in WooCommerce

Add the following code to the child-theme‘s functions.php:

// Display 24 products per page. Goes in functions.php
add_filter( 'loop_shop_per_page', create_function( '$cols', 'return 24;' ), 20 );

Replace “20” with the number of your choice.
Source: https://docs.woocommerce.com/document/change-number-of-products-displayed-per-page/