Intranet Site

I have an intranet site that is not open to public. Will WP Encryption/Let’s Encrypt work on my site? Using free plan I get the following error when trying to generate certificate.

ERROR: CREATE_CLIENT:WPLEClient\Exceptions\LEConnectorException: Invalid response: 400 (No account exists with the provided key. Please try using RESET option once. If you notice same issue again, please try after 2-3 hours.) in C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\lib\Exceptions\LEConnectorException.php:80
Stack trace:
#0 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\lib\LEConnector.php(165): WPLEClient\Exceptions\LEConnectorException::InvalidResponseException(Array)
#1 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\lib\LEConnector.php(193): WPLEClient\LEConnector->request('POST', 'https://acme-v0...', '{"protected":"e...')
#2 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\lib\LEAccount.php(112): WPLEClient\LEConnector->post('https://acme-v0...', '{"protected":"e...')
#3 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\lib\LEAccount.php(77): WPLEClient\LEAccount->getLEAccount()
#4 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\lib\LEClient.php(141): WPLEClient\LEAccount->__construct(Object(WPLEClient\LEConnector), 1, 'mcracco@torrco....', Array)
#5 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\classes\le-core.php(166): WPLEClient\LEClient->__construct('mcracco@torrco....', false, 1, 'C:\\xampp\\htdocs...')
#6 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\classes\le-core.php(146): WPLE_Core->wple_create_client()
#7 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\classes\le-core.php(115): WPLE_Core->wple_generate_verify_ssl()
#8 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\admin\le_admin.php(507): WPLE_Core->__construct(Array)
#9 C:\xampp\htdocs\torrco\wp-content\plugins\wp-letsencrypt-ssl\admin\le_admin.php(1672): WPLE_Admin->wple_save_email_generate_certs()
#10 C:\xampp\htdocs\torrco\wp-includes\class-wp-hook.php(292): WPLE_Admin->wple_admin_init_hooks('')
#11 C:\xampp\htdocs\torrco\wp-includes\class-wp-hook.php(316): WP_Hook->apply_filters(NULL, Array)
#12 C:\xampp\htdocs\torrco\wp-includes\plugin.php(484): WP_Hook->do_action(Array)
#13 C:\xampp\htdocs\torrco\wp-admin\admin.php(175): do_action('admin_init')
#14 {main}