You are creating and rendering the template all in one go, and then trying to register the two variable afterwards (with incorrect calls as well).
You need to create the class, register the variables, then render it
PHP Code:
$templater = vB_Template::create('my_template');
$templater->register('omar', $omar);
$templater->register('omar1', $omar1);
$replace = $templater->render();