How can I reference an entity field in a template file?
Change your hook_theme code to:
function mytheme_theme() {
  return [
    'node_album_edit_form' =&gt; [
      'path' =&gt; \Drupal::theme()-&gt;getActiveTheme()-&gt;getPath() . '/scss/templates/album',
      'render element' =&gt; 'form'
    ],
  ];
}

and in your template file
{{ form.field_album_title }}