Set the default settings for sending Amazon SNS SMS messages using an Amazon SDK

How to use Amazon SNS to set the DefaultSMSType attribute.

  Aws::SDKOptions options;
  Aws::InitAPI(options);
  {
    Aws::SNS::SNSClient sns;
    Aws::String sms_type =  argv[1];

    Aws::SNS::Model::SetSMSAttributesRequest ssmst_req;
    ssmst_req.AddAttributes("DefaultSMSType", sms_type);

    auto ssmst_out = sns.SetSMSAttributes(ssmst_req);

    if (ssmst_out.IsSuccess())
    {
      std::cout << "SMS Type set successfully " << std::endl;
    }
    else
    {
        std::cout << "Error while setting SMS Type: '" << ssmst_out.GetError().GetMessage()
            << "'" << std::endl;
    }
  }

  Aws::ShutdownAPI(options);

public class SetSMSAttributes {
    public static void main(String[] args) {

        HashMap<String, String> attributes = new HashMap<>(1);
        attributes.put("DefaultSMSType", "Transactional");
        attributes.put("UsageReportS3Bucket", "janbucket" );

        SnsClient snsClient = SnsClient.builder()
            .region(Region.US_EAST_1)
            .credentialsProvider(ProfileCredentialsProvider.create())
            .build();
        setSNSAttributes(snsClient, attributes);
        snsClient.close();
    }

    public static void setSNSAttributes( SnsClient snsClient, HashMap<String, String> attributes) {

        try {
            SetSmsAttributesRequest request = SetSmsAttributesRequest.builder()
                .attributes(attributes)
                .build();

            SetSmsAttributesResponse result = snsClient.setSMSAttributes(request);
            System.out.println("Set default Attributes to " + attributes + ". Status was " + result.sdkHttpResponse().statusCode());

        } catch (SnsException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

Create the client in a separate module and export it.

import  { SNSClient } from "@aws-sdk/client-sns";
// Set the AWS Region.
const REGION = "REGION"; //e.g. "us-east-1"
// Create SNS service object.
const snsClient = new SNSClient({ region: REGION });
export  { snsClient };

Import the SDK and client modules and call the API.

// Import required AWS SDK clients and commands for Node.js
import {SetSMSAttributesCommand } from "@aws-sdk/client-sns";
import {snsClient } from "./libs/snsClient.js";

// Set the parameters
const params = {
  attributes: {
    /* required */
    DefaultSMSType: "Transactional" /* highest reliability */,
    //'DefaultSMSType': 'Promotional' /* lowest cost */
  },
};

const run = async () => {
  try {
    const data = await snsClient.send(new SetSMSAttributesCommand(params));
    console.log("Success.",  data);
    return data; // For unit tests.
  } catch (err) {
    console.log("Error", err.stack);
  }
};
run();

$SnSclient = new SnsClient([
    'profile' => 'default',
    'region' => 'us-east-1',
    'version' => '2010-03-31'
]);

try {
    $result = $SnSclient->SetSMSAttributes([
        'attributes' => [
            'DefaultSMSType' => 'Transactional',
        ],
    ]);
    var_dump($result);
} catch (AwsException $e) {
    // output error message if fails
    error_log($e->getMessage());
}