Error message when trying to install HACS

I am a total newbie to Home Assistant but I can follow instructions, even if I don’t know what they are doing. I have Home Assistant running on a Home Assistant Yellow box and can access it from the Home Assistant app on my iPad and on my MacBook. Every time I run the “wget -O - https://get.hacs.xyz | bash -” command sequence ion a terminal window, I get the error message “get: connection closed prematurely” as shown in the screenshot below:

Can anyone please point me in the right direction to solve this problem - it is slowly driving me crazy!