Karate -Generate random alphanumeric string in the current feature file

I am trying to generate alphanumeric string of length 5 in Karate.I am trying the below code.

Feature: Test user

Background:

Given url AM_HOST " * def random_string =

function(s) {
  var text = "";
  var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789";
  for (var i = 0; i < s; i++)
    text += possible.charAt(Math.floor(Math.random() * possible.length));
  return text;
}

* def sessionId =  random_string(5)
* print sessionId

" " Scenario: Verify return user Given path 'user/' When method get Then status 404 And match response.message == "User Not Found" "

I am not able to run this.Can you please let me know where the code has issues.The sessionId is not printed in cucumber report also.Should the quotes before and after function be removed in the feature file.The function gets printed in report. Thanks