where you want to insert this code to get 4 columns?
add_filter( 'loop_shop_columns', 'wc_loop_shop_columns', 1, 10 );
/*
* Return a new number of maximum columns for shop archives
* @param int Original value
* @return int New number of columns
*/
function wc_loop_shop_columns( $number_columns ) {
return 4;
}
