initiating orderby on rest_api_init

add_action( 'rest_api_init', 'addOrderbySupportRest' );

function addOrderbySupportRest(){

	$post_type ="wf_account";
	// Add meta your meta field to the allowed values of the REST API orderby parameter
	add_filter(
		'rest_' . $post_type . '_collection_params',
		function( $params ) {
			$fields = ["first_name","last_name","address","email"];
			foreach ($fields as $key => $value) {
				$params['orderby']['enum'][] = $value;
			}
			return $params;
		},
		10,
		1
	);
	
	// Manipulate query
	add_filter(
		'rest_' . $post_type . '_query',
		function ( $args, $request ) {
			$fields = ["first_name","last_name","address","email"];
			$order_by = $request->get_param( 'orderby' );
			if ( isset( $order_by ) && in_array($order_by, $fields)) {
				$args['meta_key'] = $order_by;
				$args['orderby']  = 'meta_value'; // user 'meta_value_num' for numerical fields
			}
			return $args;
		},
		10,
		2
	);
} // addOrderbySupportRest function ends.