how to create a filter with elementor code example

Example: filter elementor

// Showing post with meta key filter in Portfolio Widget
add_action( 'elementor/query/my_custom_filter', function( $query ) {
	// Get current meta Query
	$meta_query = $query->get( 'meta_query' );
	// Append our meta query
	$meta_query[] = [
		'key' => 'project_type',
		'value' => [ 'design', 'development' ],
		'compare' => 'in',
	];
	$query->set( 'meta_query', $meta_query );
} );