problem in creating variables

@aabouei this is intentional.

When there are more than 30 possible variations, WooCommerce will not use conditional logic to filter what options are shown.

This is done because the calculations WooCommerce needs to do for the conditional visibility can be too much for underpowered or shared hosting sites.

You can read more about that on this post:
https://developer.woocommerce.com/2015/07/13/improving-the-variations-interface-in-2-4/

There is also a code snippet in that article that you can use to increase the number of variations that WooCommerce will dynamically calculate. Please keep in mind though that this limit was put in place to prevent site performance being impacted. So if you increase this value you may find your site being slower if it is not powerful enough.

Is it a code that you said we can use it for increase the variable logical using?

function custom_wc_admin_variations_per_page( $qty ) {
	return 20;
}

add_filter( 'woocommerce_admin_meta_boxes_variations_per_page', 'custom_wc_admin_variations_per_page' );

if is it true, where should i paste this code !??!