[Plugin: Deal with Countdown Timer] Add to Top Right (Inside Navbar)?

Hi, Thank you for making wordpress available. I’m here to learn how to make my site better.

First of all, please see my site: https://www.gbvalley.com/store/
I wish to add a timer to the top right hand corner, as shown on this picture here: https://www.gbvalley.com/upload/45136876.jpg

I read on plugin help file that i could add the following code to my theme file:
<?php if (function_exists (deal_or_announcement_with_countdown_timer_show)) deal_or_announcement_with_countdown_timer_show(); ?>

I’m using the child theme of Customizr by nikeo.

I’ve created this code in my style.css:
.navbar-inner{<?php if (function_exists (deal_or_announcement_with_countdown_timer_show)) deal_or_announcement_with_countdown_timer_show(); ?>}

But it is not working.

I’m complete new to WordPress. Coding was not my profession. Please help me find a solution to install a timer to the top right hand corner. It doesn’t have to be Deal with countdown timer either, if you have a better countdown timer that is better suit my needs.

Thank you all for your help