Here is the short custom function if you want to add a strike though on prices after coupon code.


function jp_discount( $price, $type, $amount ){

switch( $type ){
       
	case 'percent_product':
		$newprice = $price * ( 1 - $amount/100 );
		break;
	case 'fixed_product':
		$newprice = round($price - $amount,2);
		break;
	case 'percent_cart':
		$newprice = $price * ( 1 - $amount/100 );
		break;
	case 'fixed_cart':
		$newprice = $price - $amount;
		break;
	default:
	$newprice = $price;
}

return round($newprice,2);
}


function jp_woocommerce_cart_item_subtotal( $subtotal, $cart_item, $cart_item_key ){
$coupons = WC()->cart->get_coupons();    
foreach ( $coupons as $code => $coupon ) : 
	
    $newsubtotal = wc_price( jp_discount( $cart_item['line_total'], $coupon->discount_type, $coupon->amount ) ); 
    
    $categories = array(35);
    if( has_term( $categories, 'product_cat', $cart_item['product_id'] ) ) :       
		$nsubtotal =  sprintf( '%s %s', $subtotal, $newsubtotal ); 
    else:
    	$newsubtotal = wc_price($cart_item['line_total']);
    	$nsubtotal =  sprintf( ' %s', $subtotal, $newsubtotal ); 
	endif;
    
    
	return $nsubtotal;
    endforeach; 

return $subtotal;
}

add_filter( 'woocommerce_cart_item_subtotal', 'jp_woocommerce_cart_item_subtotal', 99, 3 );