How can I upload someone's shared video?

Someone has asked me to subscribe to get a video, but when I hit subscribe, I get this message:

To subscribe you need to be signed in to iCloud on:

• an iPhone, iPad, or iPod touch with iOS 6 or later, or
• a Mac with OS X 10.8.2 or later and iPhoto 9.4 or Aperture 3.4 or later

I have OS X 10.10

but when I try to download an updated iPhoto, I get the message that the app is not available in the U.S. So what am I supposed to do?