appwrite/docs/examples/0.12.x/server-dart/examples/database/create-email-attribute.md

import 'package:dart_appwrite/dart_appwrite.dart';

void main() { // Init SDK
  Client client = Client();
  Database database = Database(client);

  client
    .setEndpoint('https://[HOSTNAME_OR_IP]/v1') // Your API Endpoint
    .setProject('5df5acd0d48c2') // Your project ID
    .setKey('919c2d18fb5d4...a2ae413da83346ad2') // Your secret API key
  ;

  Future result = database.createEmailAttribute(
    collectionId: '[COLLECTION_ID]',
    key: '',
    required: false,
  );

  result
    .then((response) {
      print(response);
    }).catchError((error) {
      print(error.response);
  });
}