Drupal

{# in your theme's html.html.twig or page.html.twig #}
<invent-assistant assistant-id="YOUR_ASSISTANT_ID" />
<script type="text/javascript" src="https://www.useinvent.com/embed.js" async defer></script>

<?php
// invent_assistant.module

/**
 * Implements hook_page_attachments().
 */
function invent_assistant_page_attachments(array &$attachments) {
  $attachments['#attached']['html_head'][] = [
    [
      '#type' => 'html_tag',
      '#tag' => 'invent-assistant',
      '#attributes' => [
        'assistant-id' => 'YOUR_ASSISTANT_ID',
      ],
    ],
    'invent_assistant',
  ];

  $attachments['#attached']['html_head'][] = [
    [
      '#type' => 'html_tag',
      '#tag' => 'script',
      '#attributes' => [
        'src' => 'https://www.useinvent.com/embed.js',
        'async' => TRUE,
        'defer' => TRUE,
      ],
    ],
    'invent_assistant_script',
  ];
}

<invent-assistant
  assistant-id="YOUR_ASSISTANT_ID"
  theme-appearance="auto"
  theme-button-background-color="#0678BE"
  theme-button-color="#FFFFFF"
/>
<script type="text/javascript" src="https://www.useinvent.com/embed.js" async defer></script>

function invent_assistant_page_attachments(array &$attachments) {
  $node = \Drupal::routeMatch()->getParameter('node');

  // Only show on article nodes
  if ($node && $node->getType() == 'article') {
    // Add assistant code
  }
}

<?php
// In your theme or custom module

function invent_assistant_page_attachments(array &$attachments) {
  $current_user = \Drupal::currentUser();

  if ($current_user->isAuthenticated()) {
    $secret_key = \Drupal::config('invent_assistant.settings')->get('secret_key');
    $user_id = (string) $current_user->id();
    $user_name = $current_user->getDisplayName();
    $user_hash = hash_hmac('sha256', $user_id, $secret_key);

    $attachments['#attached']['html_head'][] = [
      [
        '#type' => 'html_tag',
        '#tag' => 'invent-assistant',
        '#attributes' => [
          'assistant-id' => 'YOUR_ASSISTANT_ID',
          'user-id' => $user_id,
          'user-name' => $user_name,
          'user-hash' => $user_hash,
        ],
      ],
      'invent_assistant',
    ];
  }
}

# your_theme.info.yml
regions:
  header: Header
  content: Content
  sidebar: Sidebar
  footer: Footer
  invent_assistant: 'Invent Assistant'

drush cr
# or
drush cache-rebuild

$attachments['#attached']['library'][] = 'your_module/invent-assistant';