This tool allows you to generate user expressions for an intent based on existing expressions.
Click on "Add Suggested User Expressions" and it will open a window with possible additional expressions you can use for your training set.
Add the ones that fit the intent by ticking the box on the left of the expression. Before adding the relevant expressions, you can adjust them by clicking on the phrase and making the change. Once you exit, it will save automatically.
To enable this feature, add at least three user expressions to the intent.