var ImageKit = require("imagekit");
var imagekit = new ImageKit({
publicKey : "your_public_api_key",
privateKey : "your_private_api_key",
urlEndpoint : "https://ik.imagekit.io/your_imagekit_id/"
var fileIds = ["file_id_1", "file_id_2"];
var tags = ["tag1", "tag2"];
imagekit.bulkAddTags(fileIds, tags, function(error, result) {
if(error) console.log(error);
else console.log(result);