sdk-for-flutter/docs/examples/account/create-phone-token.md

import 'package:appwrite/appwrite.dart';

Client client = Client()
    .setEndpoint('https://<REGION>.cloud.appwrite.io/v1') // Your API Endpoint
    .setProject('<YOUR_PROJECT_ID>'); // Your project ID

Account account = Account(client);

Token result = await account.createPhoneToken(
    userId: '<USER_ID>',
    phone: '+12065550100',
);