WoW classic Player Class API issue

I’m trying to get the class media using interface given on the documentation (https://develop.battle.net/documentation/world-of-warcraft-classic/game-data-apis)

If you go down to Playable Class Media and click try it (obviously with your client id & secret), it gives back the following response:

{
  "_links": {
    "self": {
      "href": "https://us.api.blizzard.com/data/wow/media/playable-class/1?namespace=static-1.13.6_36670-classic-us"
    }
  },
  "assets": [
    {
      "key": "icon",
      "value": "https://render-classic-us.worldofwarcraft.com/icons/56/classicon_warrior.jpg"
    }
  ]
}

That part works, but if you copy/paste the value (classicon_warrior.jpg), it fails to give an image back. I tried that link with my token and that didn’t work either.

Am I doing something wrong?