PHP中的aws-sdk加密kmsClient错误

I am very new to WAS, I want to implement a client side encryption for the DynamoDB in php. I did not find any document that can show me how to it. I tried this tutorial https://docs.aws.amazon.com/sdk-for-php/v3/developer-guide/s3-encryption-client.html, but this is for S3 not Dynamodb.

Then I tried this tutorial https://docs.aws.amazon.com/sdk-for-php/v3/developer-guide/kms-example-encrypt.html.

It shows me how to use the KmsClient to encrypt data in client side.

I change the version and region for the KmsClient to the corresponding values, the version I get from the Encryption keys page, under key policy

"Version": "2012-10-17",

The region I get

Region ap-southeast-2

I have the credential file like below in the .aws/ floder

[default]
aws_access_key_id = ***************
aws_secret_access_key = **************

I also changed the key id to the one I just created.

But I keep get this error

#0 /Users/ditto/Sites/site/php/vendor/aws/aws-sdk- 
    php/src/ClientResolver.php(427): 
    Aws\Api\ApiProvider::resolve(Object(Aws\Api\ApiProvider), 'api', 
    'kms', '2012-10-17')
#1 /Users/ditto/Sites/site/php/vendor/aws/aws-sdk- 
    php/src/ClientResolver.php(288): 
  Aws\ClientResolver::_apply_api_provider(Object(Aws\Api\ApiProvider), 
    Array, Object(Aws\HandlerList))
#2 /Users/ditto/Sites/site/php/vendor/aws/aws-sdk- 
   php/src/AwsClient.php(158): Aws\ClientResolver->resolve(Array, 
   Object(Aws\HandlerList))
#3 /Users/ditto/Sites/site/php/signUpCopy.php(22): 
   Aws\AwsClient->__construct(Array)
#4 {main}
    thrown in /Users/ditto/Sites/site/php/vendor/aws/aws-sdk-php/src/Api/ApiProvider.php on line 85

This is my code:

include ('config.php');

require ('vendor/autoload.php');

use Aws\Kms\KmsClient;
use Aws\Exception\AwsException;    

$message = pack('c*',1,2,3,4,5,6,7,8,9,0);

$KmsClient = new Aws\Kms\KmsClient([
    'profile' => 'default',
    'version' => '2012-10-17',
    'region' => 'ap-southeast-2'
]);
 $keyId = '***************************';


$message = pack('c*', 1, 2, 3, 4, 5, 6, 7, 8, 9, 0);

try {
    $result = $KmsClient->encrypt([
        'KeyId' => $keyId,
        'Plaintext' => $message,
    ]);
    var_dump($result);
} catch (AwsException $e) {
    // output error message if fails
    echo $e->getMessage();
    echo "
";
}

I do not know where I did it wrong.