sdk-for-dart/docs/examples/functions/create-template-deployment.md

import 'package:dart_appwrite/dart_appwrite.dart';
import 'package:dart_appwrite/enums.dart' as enums;

Client client = 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

Functions functions = Functions(client);

Deployment result = await functions.createTemplateDeployment(
    functionId: '<FUNCTION_ID>',
    repository: '<REPOSITORY>',
    owner: '<OWNER>',
    rootDirectory: '<ROOT_DIRECTORY>',
    type: enums.TemplateReferenceType.commit,
    reference: '<REFERENCE>',
    activate: false, // (optional)
);