Currently, the request for changing account type is not supported yet. Alternatively, an additional account can be applied according to your preferred account type.
Simply go to your Client Portal and select Account > Open additional accounts to apply for additional accounts. You will receive an auto-email about the login information of your additional account once you finish applying for it.
Click this link for the full guide on how to request an additional trading account.
If you have other questions about applying for additional accounts, please contact live chat customer service.