I have an semester field. I want to display a text "required" if the field is empty, and hide the text if the field is not empty

This is done by placeholder text, not by conditional formatting: 
https://help.claris.com/en/pro-help/content/adding-changing-field-labels.html

Or, if you want to place the text outside the field, just hide it when:

IsEmpty ( YourTable::Semester )

https://help.claris.com/en/pro-help/content/hiding-showing-objects.html

 

Edited June 3, 20241 yr by comment