Im working out an integration with AWS Pinpoint with the AWS PHP SDK v3. In documentation for the function sendMessages there is no parameter to pass in the template ARN. Yet i get an error that demands an template ARN:

PERMANENT_FAILURE [StatusCode] => 400 [StatusMessage] => Request must include template ARN.

Currently have this function defined for sending the message:

public function sendMessage($id = null)
{
    $this->autoRender = false;
    $this->Authorization->skipAuthorization();

    // Initialize the AWS SDK
    $credentials = CredentialProvider::sso('dev-sso');

    $client = new PinpointClient([
        'region' => 'eu-central-1',
        'credentials' => $credentials,
    ]);

    $Message= $this->Messages->get($id, contain: []);

    $templateArn = 'arn:aws:mobiletargeting:eu-central-1:xxxxxx:templates/xxxxxx/EMAIL';

    $params = [
        'ApplicationId' => 'xxxxxx',
        'MessageRequest' => [
            'Addresses' => [
                '[email protected]' => [
                    'ChannelType' => 'EMAIL',
                ],
            ],
            'MessageConfiguration' => [
                'EmailMessage' => [
                    'FromAddress' => '[email protected]',

                ],
                'TemplateConfiguration' => [
                    'EmailTemplate' => [
                        'Name' => $Message->id,
                        'TemplateArn' => $templateArn
                        'Version' => 'latest',
                    ],
                ],
            ],
        ]
    ];

    try {
        $result = $client->sendMessages($params);
        print_r($result);
    } catch (AwsException $e) {
        // output error message if fails
        dd($e->getMessage());
    }
}

I’ve tried placing the ARN in multiple positions in the parameters that would make sense, but cant seem to find anything that works. Help pls