You are running NuGet.Server v3.4.1.0

Click here to view your packages.

Repository URLs In the package manager settings, add the following URL to the list of Package Sources:
https://s2snuget.azurewebsites.net/nuget
Use the command below to push packages to this feed using the NuGet command line tool (nuget.exe).
nuget.exe push {package file} {apikey} -Source https://s2snuget.azurewebsites.net/nuget