SSH is only required for the Ambari server to bootstrap the agents. There is an option to bootstrap the agents manually so you don't need SSH.
In the wizard UI, on the "Install Options" page, uncheck + do not provide your SSH key. You will get a warning telling you need to manually bootstrap the agents instead.
Following these instructions, your IT department can install the agent(s) on the target host(s) and start them so they register with the Ambari server. Avoids you having to use root SSH. Have IT install and start all the agents, then you can run thru the install wizard w/o SSH.