No, you don't need to open a new account. Please login to IB's account management site at https://www.interactivebrokers.com/sso/Login , then by follow IB's instructions to move your entire account, create a linked account, or partition your account. You will need to fill out this form (select to autotrade in an existing Interactive Brokers account) to request Global AutoTrading's account information to fill out IB's linking forms.
If the menu item to link your account is missing, please contact IB to ask why you cannot link your account to an advisor/broker. This seems to happen when an account has been "linked" to create a second IB account. If that is the case for your account, your best bet is probably to open another account with IB using this link (which will create a new account, already associated with Global AutoTrading and ready for autotrading).