You've come to the right place, Tommys.
I've got just the steps that'll help set up the Roth IRA. Let me walk you through the process:
Set up Deductions & Contributions
For future reference, I'm also including this article: Set up a Roth 401(k) plan
That should do it. Let me know if you need further assistance with this, or if there's anything else I can do for you. Have a great day!