Missing required client configuration 'region'

On initial setup, after providing the required AWS Connector Credentials and saving the config form getting following error.

The website encountered an unexpected error. Please try again later.</br></br><em class="placeholder">InvalidArgumentException</em>: Missing required client configuration options: 

region: (string)

  A &quot;region&quot; configuration value is required for the &quot;iot&quot; service
  (e.g., &quot;us-west-2&quot;). A list of available public regions and endpoints can be
  found at http://docs.aws.amazon.com/general/latest/gr/rande.html. in <em class="placeholder">Aws\ClientResolver-&gt;throwRequired()</em> (line <em class="placeholder">377</em> of <em class="placeholder">/var/www/newell/vendor/aws/aws-sdk-php/src/ClientResolver.php</em>). <pre class="backtrace">Aws\ClientResolver-&gt;resolve(Array, Object) (Line: 166)
Aws\AwsClient-&gt;__construct(Array) (Line: 117)
Drupal\aws_connector\Credentials\AWSCredentialProvider::validateCredentials(&#039;AKIAI7WVQBD574QSWFCQ&#039;, &#039;KIAI7WVQBD574QSWFCQ.X5VQKgmTSw2Awq0SP2wYq5LEhGd4thTDgbWg45sx&#039;) (Line: 90)
Drupal\aws_connector\Form\AWSConnectorForm-&gt;validateForm(Array, Object)
call_user_func_array(Array, Array) (Line: 82)
Drupal\Core\Form\FormValidator-&gt;executeValidateHandlers(Array, Object) (Line: 275)
Drupal\Core\Form\FormValidator-&gt;doValidateForm(Array, Object, &#039;aws_connector_form&#039;) (Line: 118)
Drupal\Core\Form\FormValidator-&gt;validateForm(&#039;aws_connector_form&#039;, Array, Object) (Line: 575)
Drupal\Core\Form\FormBuilder-&gt;processForm(&#039;aws_connector_form&#039;, Array, Object) (Line: 318)
Drupal\Core\Form\FormBuilder-&gt;buildForm(&#039;aws_connector_form&#039;, Object) (Line: 93)
Drupal\Core\Controller\FormController-&gt;getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber-&gt;Drupal\Core\EventSubscriber\{closure}() (Line: 582)
Drupal\Core\Render\Renderer-&gt;executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber-&gt;wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber-&gt;Drupal\Core\EventSubscriber\{closure}() (Line: 151)
Symfony\Component\HttpKernel\HttpKernel-&gt;handleRaw(Object, 1) (Line: 68)
Symfony\Component\HttpKernel\HttpKernel-&gt;handle(Object, 1, 1) (Line: 67)
Drupal\simple_oauth\HttpMiddleware\BasicAuthSwap-&gt;handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session-&gt;handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle-&gt;handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache-&gt;pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache-&gt;handle(Object, 1, 1) (Line: 51)
Drupal\jsonapi\StackMiddleware\FormatSetter-&gt;handle(Object, 1, 1) (Line: 99)
Drupal\shield\ShieldMiddleware-&gt;handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware-&gt;handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware-&gt;handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel-&gt;handle(Object, 1, 1) (Line: 669)
Drupal\Core\DrupalKernel-&gt;handle(Object) (Line: 19)
</pre>

Although, the AWS Region value was present on the form.
However, while validating the credentials, following always returns NULL as the config for region(aws_region) was not set during module install.
return $aws_connector_config->get('aws_connector.' . $key);

As the AWS Region is required, the default config should be set when module gets installed.