kuniiman on "[Plugin: AWeber Forms by Optin Cat] Sidebar Not Working"

I have a popup signup and a sidebar signup and I am not able to get the sidebar signup on my site. I have tried going to the Appearance > Widgets setting but when I add the Optin Cat Sidebar Widget to either the Left Sidebar or Signup Sidebar I am not able able to see it when I refresh the page. Am I missing a step to adding the sidebar signup to the sidebar?

https://wordpress.org/plugins/aweber-wp/