How to show Top Bar only in one page

Hi there,

that Top Bar is not part of the theme, how is it being added to your site ?

With a plugin.

Does the plugin automatically display the top bar ? If so you would need to check with the Plugin Developer.
If the plugin provides a Shortcode option to display the Top Bar, then you can try adding it using a Hook Element, in the before_header hook to display it. You can then set the Display Rules for the page you want it displayed on.