For example, making sure we set a unique user name value in an input field. In this case you can set the value to this simple expression:
'user' + Date.now().
When running, Testim will evaluate the expression and set its text in the field:
Using a parameter
For example if I have exported from a prior step the user name to the parameter
I can now set its value to the user name field by just writing its name in the Text to Assign field: