gistfile1.txt

add_action( 'elementor/query/onmarketpropertyquery', 'handle_sold_tickbox' );
function handle_sold_tickbox($query)
{
	$tax_query = $q->get('tax_query');
	
	if ( !isset($_GET['include_sold_stc']) )
	{
		// Not ticked. Only include available properties
		if (!is_array($tax_query)) { $tax_query = array(); }

        $tax_query[] = array(
            'taxonomy' => 'availability',
            'field' => 'term_id',
            'terms' => array(20, 24), // 20 = For sale, 24 = To Let
            'operator' => 'IN'
        );
	}
	
	$query->set( 'tax_query', $tax_query );
}