How do I ensure that my Cumulative Layout Shift score is not affected?

Google provides a Core Web Vitals report, which provides various data about how your pages perform.  More information about this can be found here - https://support.google.com/webmasters/answer/9205520?hl=en 

Although our Countdown Timer Bar app does not negatively affect your website's performance, one of the categories that is reported is Cumulative Layout Shift (CLS).  If your CLS score has been affected after installing our app and you want to improve the score,  please use one of the following display  positions:

- Top bar overlaps the top of the page
- Top bar overlaps the top of the page (always visible while scrolling)
- Bottom bar overlaps the bottom of the page (always visible while scrolling)

The other display positions will shift the page to avoid covering content and this could lower your CLS score.