I had also faced similar situation , in my case following 3 points needed to be changed :

1. Make sure your Sitecore License has JSS license included , you can check this from licenses

2. Make sure you have installed the JSS Server Components Sitecore package throught installation wizard as per your Sitecore instance version from following link. https://dev.sitecore.net/Downloads/Sitecore_JavaScript_Services.aspx

3. Make sure that JSS setup command is executed and you are prompted to provide option , provide the app name of your jss app in Siecore hostname , similarly Sitecore Service URL as shown below. Off course new IIS site binding and host entry is also required. Also make sure no VPN or proxy is affecting your copying.

I had also faced similar situation , in my case following 3 points needed to be changed :

1. Make sure your Sitecore License has JSS license included , you can check this from licenses

2. Make sure you have installed the JSS Server Components Sitecore package through installation wizard as per your Sitecore instance version from following link. https://dev.sitecore.net/Downloads/Sitecore_JavaScript_Services.aspx

3. Make sure that when JSS setup command is executed and you are prompted to provide option , provide the app name of your jss app in Sitecore hostname , similarly Sitecore Service URL as shown below. Of course new IIS site binding and host entry is also required. Also make sure no VPN or proxy is affecting your copying.