IBKR does not allow a single user name to operate multiple sessions concurrently. Operating multiple trading applications for a given account simultaneously requires a separate user name (for information on adding another user, see: Can I create a second user name for my account?).
While there is no charge to request an additional user name, vendor rules prohibit the sharing of market data by distinct users (whether the same individual or not), thereby requiring a separate subscription for any live price feeds that additional user desires.