Is it possible to separate 2.4 GHz and 5 GHz bands on MR60?

So, I need separated username for 2.4 band and user manual says it possible:

To add a WiFi network:
1. Launch a web browser from a computer or mobile device that is connected to your
mesh network.
2. Enter http://www.routerlogin.net.
A login window opens.
3. Enter the router admin user name and password.
The user name is admin. The password is the one that you specified the first time
that you logged in. The user name and password are case-sensitive.
The BASIC Home page displays.
4. Select Customize WiFi Network.
The Customize WiFi Network page displays.
5. Select the Customize 2.4 GHz WiFi Network or Customize 5 GHz WiFi Network
check box.
You can add a WiFi network in the 2.4 GHz band and the 5 GHz band.

BUT in reality there is no any Customize WiFi Network menu and all those options, see the screen. Any suggestions?