Ascora Enquiry API Returning "No Content" when utilising wp_remote_post

Question

I am trying to submit enquiries into Ascora using their Enquiry API.

I have created a WordPress plugin and I am trying to send the payload using wp_remote_post.

If any of you kind folk can spot my mistake, and let me know how I can get this working, I would greatly appreciate it.

Here is the code that I have written:

    if( ! class_exists( 'Forminator_Ascora_Integration' ) ) {
    
    class Forminator_Ascora_Integration {
        
        private $endpoint, $token;
        
        public function __construct() {
            
            $this->endpoint = "https://api.ascora.com.au/Enquiry";
            $this->token = "OMITTED-FOR-SO";
            
            add_action( 'forminator_custom_form_submit_before_set_fields', array( $this, 'after_forminator_submission'), 10, 3 );
            
        }
        
        public function after_forminator_submission( $entry, $form_id, $submission_data ) {
            
            $submitted_enquiry = null;
            
            // General Enquiries
            if( $form_id == 1564 ) {
                $submitted_enquiry = array(
                    'firstName'             =>  $submission_data[0]['value'],
                    'lastName'              =>  $submission_data[1]['value'],
                    'companyName'           =>  $submission_data[2]['value'],
                    'email'                 =>  $submission_data[3]['value'],
                    'phone'                 =>  $submission_data[4]['value'],
                    'enquiryDescription'    =>  $submission_data[5]['value'],
                );
            }
            
            if( is_array ($submitted_enquiry ) ) {
                $this->send_data_to_ascora( $submitted_enquiry );
            }
            
        }
        
        private function send_data_to_ascora( $submitted_enquiry = array() ) {
            
            $default_enquiry = array(
                'companyName'           =>  '',
                'firstName'             =>  '',
                'lastName'              =>  '',
                'email'                 =>  '',
                'phone'                 =>  '',
                'mobile'                =>  '',
                'addressLine1'          =>  '',
                'addressLine2'          =>  '',
                'addressSuburb'         =>  '',
                'addressPostcode'       =>  '',
                'addressCountry'        =>  '',
                'enquiryDescription'    =>  '',
            );
            
            $enquiry = array_merge( $default_enquiry, $submitted_enquiry );
            
            $payload = array(
                'method'        =>  'POST',
                'headers'       =>  array(
                    'Auth'          =>  $this->token,
                    'Content-Type'  =>  'application/json; charset=utf-8'
                ),
                'body'          =>  json_encode( $enquiry ),
                'timeout'       =>  30,
                'httpversion'   => '1.1',
            );
            
            $response = wp_remote_post( $this->endpoint, $payload );
            
            wp_mail( 'OMITTED-FOR-SO', 'Payload Sent', "<pre>" . var_export( $payload, true ) . "</pre>", array('Content-Type: text/html; charset=UTF-8') );
            wp_mail( 'OMITTED-FOR-SO', 'API Response', "<pre>" . var_export( $response, true ) . "</pre>", array('Content-Type: text/html; charset=UTF-8') );
            
            $resonse_error = null;
            
            if( is_wp_error( $response ) ) {
                $response_error = 'Error Found:' . $response->get_error_message();
            }
            
            if( $response_error ) {
                error_log( print_r( $response_error, true ) );
                
            }
            
        }
        
    }
    
}

new Forminator_Ascora_Integration();

As you can see in the source code, for testing purposes I am sending myself two emails.

Here is the content of those emails respectively.

Payload:

array (
  'method' => 'POST',
  'headers' => 
  array (
    'Auth' => 'OMITTED-FOR-SO',
    'Content-Type' => 'application/json; charset=utf-8',
  ),
  'body' => '{"companyName":"OMITTED-FOR-SO","firstName":"OMITTED-FOR-SO","lastName":"OMITTED-FOR-SO","email":"OMITTED-FOR-SO","phone":"OMITTED-FOR-SO","mobile":"","addressLine1":"","addressLine2":"","addressSuburb":"","addressPostcode":"","addressCountry":"","enquiryDescription":"Testing."}',
  'timeout' => 30,
  'httpversion' => '1.1',
)

API Response:

    array (
  'headers' => 
  Requests_Utility_CaseInsensitiveDictionary::__set_state(array(
     'data' => 
    array (
      'server' => 'Microsoft-IIS/10.0',
      'x-powered-by' => 'ASP.NET',
      'access-control-allow-origin' => '*',
      'access-control-allow-headers' => 'Content-Type, Authorization, Auth',
      'access-control-allow-methods' => 'GET, POST, PUT, DELETE, OPTIONS',
      'date' => 'Fri, 20 May 2022 05:04:08 GMT',
    ),
  )),
  'body' => '',
  'response' => 
  array (
    'code' => 204,
    'message' => 'No Content',
  ),
  'cookies' => 
  array (
  ),
  'filename' => NULL,
  'http_response' => 
  WP_HTTP_Requests_Response::__set_state(array(
     'response' => 
    Requests_Response::__set_state(array(
       'body' => '',
       'raw' => 'HTTP/1.1 204 No Content
Server: Microsoft-IIS/10.0
X-Powered-By: ASP.NET
Access-Control-Allow-Origin: *
Access-Control-Allow-Headers: Content-Type, Authorization, Auth
Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS
Date: Fri, 20 May 2022 05:04:08 GMT
Connection: close

',
       'headers' => 
      Requests_Response_Headers::__set_state(array(
         'data' => 
        array (
          'server' => 
          array (
            0 => 'Microsoft-IIS/10.0',
          ),
          'x-powered-by' => 
          array (
            0 => 'ASP.NET',
          ),
          'access-control-allow-origin' => 
          array (
            0 => '*',
          ),
          'access-control-allow-headers' => 
          array (
            0 => 'Content-Type, Authorization, Auth',
          ),
          'access-control-allow-methods' => 
          array (
            0 => 'GET, POST, PUT, DELETE, OPTIONS',
          ),
          'date' => 
          array (
            0 => 'Fri, 20 May 2022 05:04:08 GMT',
          ),
        ),
      )),
       'status_code' => 204,
       'protocol_version' => 1.1,
       'success' => true,
       'redirects' => 0,
       'url' => 'https://api.ascora.com.au/Enquiry',
       'history' => 
      array (
      ),
       'cookies' => 
      Requests_Cookie_Jar::__set_state(array(
         'cookies' => 
        array (
        ),
      )),
    )),
     'filename' => NULL,
     'data' => NULL,
     'headers' => NULL,
     'status' => NULL,
  )),
)