Hafnium: ProxyLogon (Offensive) - Question 3

For the FQDN, I am wondering about where I am going wrong 

 as I am basically using the command expected of this lab. However, there wasn't any shell code provided nor any expecations of what the shell powershell script should contain. I am wondering if you could provide directions into where I should be digging deeper into, to be able to obtain the FQDN