Use Row IDs
We recommend using the Row ID column instead of the Unique ID special value. Learn more here.
The Unique Identifier is a special value that you can assign to a row when users add, edit, or submit forms. This unique identifier gives you additional control over relations between items in your app.
In the Layout Editor, select the tab you want to edit.
Click on the plus (+) symbol in the Components panel.
Search for Unique Identifier and or go to Special Values -> Unique Identifier.
The Unique Identifier can only be added to screens where users can add, edit, or submit new entries.
In the configuration settings on the right of the Layout Editor, choose the column where the unique values will be stored.