Reinstall OS X El Captain

I did a restore on my older iMac, when I go to do the reinstall for OS X El Captain it will prompt me to enter my apple id and password to connect to the app store. I do so, follow the two-factor authorization and then while it is loading it'll pop up with a message that says "This item is temporarily unavailable, try again later". It's connected to our wifi and I don't see any other options for install. How do I get past this?