Templates aren't called in custom module? I am trying to add templates for the paragraph in the custom module. It invokes only the paragraph.html.twig.

In theme suggestion, paragraph--example-ch-hero-panel.html.twig is given. I am using the same templates. By default, The template will be taken for the paragraph here. But here its not working. I am not using hook_theme in .module for this. because I am not passing any values to the templates.

even try this also

function example_ch_hero_panel_theme() {
  return [
    'paragraph__example_ch_hero_panel' =&gt; [
      'render element' =&gt; 'element',
      'template' =&gt; 'paragraph--example-ch-hero-panel',
      'base hook' =&gt; 'paragraph',
    ],
  ];
}


added theme registry too

function example_ch_hero_panel_theme_registry_alter(&amp;$theme_registry) {
  $theme_registry['page']['path'] = drupal_get_path('module', 'example_ch_hero_panel') . '/templates';
}



  Please try again later.Twig\Error\LoaderError: Template
  &quot;modules/custom/example_ch_hero_panel/templates/page.html.twig&quot;
  is not defined. in Twig\Loader\ChainLoader-&gt;getCacheKey()


can anyone sort out this issue.
Your problem is coming from this code:

$theme_registry['page']['path'] = drupal_get_path('module', 'example_ch_hero_panel') . '/templates';


The first array key, page, means you are working the page template. You've told the system to look for page.html.twig in your module's /templates directory. It's not finding it, so you get that error.

Remove that hook altogether, it's not the right way to do what you are trying to do.