Error installing Gitlab on Red Hat 7

Hi! I was assigned a project to install GitLab on a server so i tried first on a lab server. I am running Red Hat Enterprise Linux Server release 7.3 (Maipo). I followed the stepts here Download and install GitLab | GitLab but i am stuck at step 2. When i run this command

curl | sudo bash

i am getting this error:

Downloading repository file:
curl: (7) Failed connect to; Connection refused

Unable to run:

Double check your curl installation and try again.

I tried executing curl by itself but i am getting a 404, strange thing is that in my browser (outside the server) i am putting that URL and it gives me information. I configured the proxy, which is working because both curl and curl works, so i have internet access, do you know what’s happening? or what could be the problem? I didn’t find much information on google search, so i decided to come to the source, aka, here
Thanks a lot for help