sdk-for-dart/docs/examples/account/create-session.md

import 'package:dart_appwrite/dart_appwrite.dart';

Client client = Client()
    .setEndpoint('https://<REGION>.cloud.appwrite.io/v1') // Your API Endpoint
    .setProject('<YOUR_PROJECT_ID>') // Your project ID
    .setSession(''); // The user session to authenticate with

Account account = Account(client);

Session result = await account.createSession(
    userId: '<USER_ID>',
    secret: '<SECRET>',
);