create-index.md

const sdk = require('node-appwrite');

const client = new sdk.Client()
    .setEndpoint('https://<REGION>.cloud.appwrite.io/v1') // Your API Endpoint
    .setProject('<YOUR_PROJECT_ID>') // Your project ID
    .setKey('<YOUR_API_KEY>'); // Your secret API key

const databases = new sdk.Databases(client);

const result = await databases.createIndex({
    databaseId: '<DATABASE_ID>',
    collectionId: '<COLLECTION_ID>',
    key: '',
    type: sdk.DatabasesIndexType.Key,
    attributes: [],
    orders: [sdk.OrderBy.Asc], // optional
    lengths: [] // optional
});