I am collecting emails from users who visited my website

I am collecting emails from users who visited my website via subscribe by email plugin. As you know, this plugin introduces a widget which includes a form to collect emails. I would like to use same form to collect emails in a popup. For this reason, I am also using your Wordpress Pop up plugin. I am using the following code in the Wordpress popup plugin, popover. This is the same code that is being used in the widget. However, for some reason, the code which works in the widget, does not work in the popover. I can display it fine. However, when I click to subscribe, it does not collect emails. Can you help me with that?

<form id="subscribe-by-email-subscribe-form" method="post">
<p> </p>
<p class="subscribe-by-email-error">Please enter your email.</p>
<p class="subscribe-by-email-updated">Thanks</p>
<input class="subscribe-by-email-field" type="email" placeholder="enter email name="subscription-email">
<input type="hidden" value="sbe_subscribe_user" name="action">
<input class="subscribe-by-email-submit" type="submit" value="Subscribe" name="submit-subscribe-user">
<img class="subscribe-by-email-loader" src="http://mywebsite.com/wp-content/plugins/subscribe-by-email/assets/images/ajax-loader.gif" style="display: none;">