Automatic Google translation when there is no real translation
I have an idea that we can achieve using gtranslate language dropdown (hidden) and drupal langauge dropdown

Steps
in hook_preprocess_page check node has translation if yes make the page is not google translatable using class "notranslate"
if it has not translation then pass the language code to javascript and call google translate function

For Exampel:
/**
 * Implements hook_preprocess_page().
 */
function hook_preprocess_page(&amp;$variables) {
  $variables['attributes']['class'] = [];
    $language = \Drupal::languageManager()->getCurrentLanguage()->getId();

$variables['attributes']['class'][] = 'node-' . $nid;

if(isset($variables['node'])) {
    $nid = $variables['node']-&gt;id();

    if($variables['node']-&gt;hasTranslation($language)) {
        $variables['attributes']['class'][] = 'notranslate';
    }
    else {
        $variables['#attached']['drupalSettings']['language'] = $language;
    }
}


}

In Custom.js

doGTranslate('en|' + drupalSettings.language);