When importing test cases w/Xray for Jira, what field is used to identify user role running test?

[Nancy McGuire]

I am trying to import test cases with preconditions that you log in as a specific user role to execute the tests. But XRay won't allow me to. It doesn't like what's in the "preconditions" field. What other field do I use? I tried assignee name and that didn't take either.