Invalid url: URL host must be one of: localhost, <IP> (400)

  if (req.variables['APPWRITE_FUNCTION_ENDPOINT'] == null || req.variables['APPWRITE_FUNCTION_API_KEY'] == null) {
    print("Environment variables are not set. Function cannot use Appwrite SDK.");
    return;
  }
  try {
    print("Initing function");

    final client = Client();

    client
        .setEndpoint(req.variables['APPWRITE_FUNCTION_ENDPOINT'])
        .setProject(req.variables['APPWRITE_FUNCTION_PROJECT_ID'])
        .setKey(req.variables['APPWRITE_FUNCTION_API_KEY'])
        .setSelfSigned(status: true);

    final teams = Teams(client);

    print("client init");
    print("Data type: ${req.payload.runtimeType}");
    print("Data: ${req.payload}");
    Map<String, dynamic> payload = jsonDecode(req.payload.replaceAll("\n", ""));

    String businessID = payload['businessID'];
    String email = payload['email'];

    print("businessID: " + businessID);
    print("email: " + email);

    await teams.createMembership(
      teamId: 'business',
      email: email,
      roles: [],
      url: 'url.com'
    );
    res.json({
      'success': true,
    });
  } catch (e) {
    print("Error: $e");
    res.json({
      'success': false,
    });
  }

Initing function
client init
Data type: String
Data: {"businessID": "hello","email": "email@email.com"}
businessID: hello
email: email@email.com
Error: AppwriteException: general_argument_invalid, Invalid url: URL host must be one of: localhost, <IP> (400)