Welcome to the community!
I assume you're referring to the Caller-ID name? If yes, you should be able to do so via your My Account --> Usage & Services --> Choose Phone number. If you do not initially see the Usage & Services tab, you might need to first click on Profile & Settings or Billings tab. Once on the page associated with the proper line, the option to change call display name is near the bottom under Quick Actions (see here).
Hope this helps 😀