Is it possible to have pre-load elements in webforms? I have to add two elements (checkbox, texfield) in the creation process of the webform. This is because I want a simple terms and conditions inside all webforms. How can I do this?
You could pre-load the elements in a hook_ENTITY_TYPE_create hook: 

mymodule.module:

  /**
   * Implements hook_ENTITY_TYPE_create() for webform entities.
   */
  function mymodule_webform_create(\Drupal\webform\WebformInterface $webform) {

    $elements = [
      'name' =&gt; [
        '#type' =&gt; 'textfield',
        '#title' =&gt; 'name',
      ],
      'other' =&gt; [
        '#type' =&gt; 'textfield',
        '#title' =&gt; 'other',
      ],
    ];

    $webform-&gt;setElements($elements);
  }