By default, your Notice will appear on the App for 24 hours. After this time, it will no longer be available.
However, you can change the settings so it is available for one week, one month or until a custom date. If you have a notice that you want to be available on your app permanently, set the custom date and change the year to one that’s far in the future (for example, in 3000).
Once you've done that, hit 'Save' and your Notice won't disappear.