Access Token Information Not Working

I was testing the new authorization service and I was calling the API to get the access token information using:

https://api.cc.email/v3/token_info

See

https://v3.developer.constantcontact.com/api_reference/index.html#!/Access_Token_Information/postAuthCode

I get the following error back:

[ { "error_key": "token.invalid", "error_message": "Invalid access token" } ]

However, the token I was testing is valid.

I know it is valid since it works with other API calls.

Testing it from the above link from the documentation produces the same results.