How to enforce Fast Formula to trigger only upon clicking on submitted absence entries ?

Summary:

Customer wants to enforce error messages on Add Absence page, tested on Submit button is working fine however when I clicked on Save and close and again submitting it after addition of one more entry of absence then also it is throwing error message. How to check if leave is in submitted status

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

23D

Code Snippet (add any code snippets that support your topic, if applicable):