hook_preprocess_views_view_field

hook_preprocess_views_view_field.php

<?php

/**
 * Implements hook_preprocess_views_view_field().
 */
function MODULE_preprocess_views_view_field(&$variables) {
  /** @var \Drupal\views\ViewExecutable $view */
  $view = $variables['view'];
  if ($view->id() == 'schedule') {
    if ($view->current_display == 'embed_1') {
        $variables['output'] = 'awdaDAWDawd';
      }
    }
  }
}