How to render a form in custom template?
'render element' => 'form'


Your render element is form which means all provided variables will be passed there.

In your twig template you can render your form like here

&lt;div&gt;{{ form.form }}&lt;/div&gt;




UPDATE #1

Wow man, you have wrong namespace Drupal\cmodule\Forms\RequestForm

Should be Drupal\cmodule\Form\RequestForm

Please rename Forms to Form (the same for directory) and clear cache. It should help you.