Hide custom fields box from edit page

Please ad the given code in your wp-content/plugins/wplms-customizer/wplms-customizer.php file:

function remove_my_page_metaboxes() {
remove_meta_box( 'postcustom','question','normal' );
remove_meta_box( 'postcustom','quiz','normal' );
remove_meta_box( 'postcustom','wplms-assignment','normal' );
remove_meta_box( 'postcustom','unit','normal' );
remove_meta_box( 'postcustom','course','normal' );
}
add_action('admin_menu','remove_my_page_metaboxes');