Well, the ICX7150 is not a router is a Swith, its function is to be the device that allows you to connect multiple wired devices from your ISP router and provide PoE (power over Ethernet) to your devices such as doorbells, cameras, even Access Points, now if you have completed the configuration of the Unleashed network you should have internet connection to the network you have created if not, it is because the Switch may not be connected to your ISP router which is responsible for providing internet to the Switch and Access Points Unleashed, please review the following guide on how the connections should go, and finally the option to see the switch ICX7150 as your connected devices from the APP unleashed or from the Dashboard is mostly for monitoring, let me add the guide to associate it, now with the password that you could during this process try with the same password that you use for the APP or the Unleashed Dashboard, if it doesn't work you must log in to the Switch to see what user and password is created; however, for this you need to log in remotely, either by SSH or Telnet or by console, I will also give you a guide on how to login and what commands to run so that we can see the configuration and help you.
Most common Setups for Lennar homes users
Ruckus at Home: Introduction(Tutorial video)
ICX Switch Management Overview
Approving a New Switch to Join Unleashed
How to console in the ICX-7150-12CP 'Ruckus Switch'
RUCKUS ICX 7150 USB TYPE C CONSOLE (tutorial video)
How to Access an ICX Switch remotely via SSH or Telnet, using a Windows computer
Command to share ones you gain access to the switch in case the password still no working: